SB2026072616 - Multiple vulnerabilities in Confluence Data Center



SB2026072616 - Multiple vulnerabilities in Confluence Data Center

Published: July 26, 2026

Security Bulletin ID SB2026072616
CSH Severity
High
Patch available
YES
Number of vulnerabilities 24
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

High 17% Medium 79% Low 4%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 24 vulnerabilities.


1) Prototype pollution (CVE-ID: CVE-2026-44490)

CWE-ID: CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes (\'Prototype Pollution\')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/U:Green


The vulnerability allows a remote attacker to execute arbitrary JavaScript code.

The vulnerability exists due to improper input validation in the merge() function in lib/utils.js. A remote attacker can pass specially crafted input to the application and perform prototype pollution, which can result in data manipulation or denial of service (DoS) condition.


2) Server-Side Request Forgery (SSRF) (CVE-ID: CVE-2025-62718)

CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:L/SC:L/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to conduct server-side request forgery and disclose sensitive information.

The vulnerability exists due to improper hostname normalization in NO_PROXY rule evaluation when processing attacker-controlled request URLs. A remote attacker can supply a crafted URL using forms such as localhost. or [::1] to conduct server-side request forgery and disclose sensitive information.

Applications that rely on NO_PROXY entries for loopback or internal services are affected.


3) Path traversal (CVE-ID: CVE-2026-6321)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to bypass path-based policy checks.

The vulnerability exists due to path traversal in the normalize() and equal() functions when processing percent-encoded path separators and dot segments in attacker-controlled URLs. A remote attacker can supply a specially crafted URL to bypass path-based policy checks.

Applications that normalize or compare attacker-controlled URLs to enforce path-based policy are affected.


4) Interpretation Conflict (CVE-ID: CVE-2026-6322)

CWE-ID: CWE-436 - Interpretation Conflict

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to bypass host-based security checks and route requests to an unintended authority.

The vulnerability exists due to interpretation conflict in the URI host component when processing percent-encoded authority delimiters. A remote attacker can supply a specially crafted URL to bypass host-based security checks and route requests to an unintended authority.

This issue can affect applications that normalize untrusted URLs before host allowlist checks, redirect validation, or outbound request routing.


5) Code Injection (CVE-ID: CVE-2026-4800)

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to improper control of code generation in _.template when processing untrusted options.imports key names. A remote attacker can supply crafted imports key names to execute arbitrary code.

Code execution occurs at template compilation time. If Object.prototype has been polluted by another vector, inherited polluted keys can also be copied into the imports object and passed to Function().


6) Permissive List of Allowed Inputs (CVE-ID: CVE-2026-42043)

CWE-ID: CWE-183 - Permissive List of Allowed Inputs

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to bypass proxy restrictions and disclose sensitive information.

The vulnerability exists due to permissive list of allowed inputs in lib/helpers/shouldBypassProxy.js when processing Axios requests to loopback addresses in the 127.0.0.0/8 range. A remote attacker can influence the target URL to bypass proxy restrictions and disclose sensitive information.

Exploitation requires the application to use proxy environment variables and rely on NO_PROXY rules to protect loopback services.


7) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2026-42583)

CWE-ID: CWE-770 - Allocation of Resources Without Limits or Throttling

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to uncontrolled resource consumption in io.netty.handler.codec.compression.Lz4FrameDecoder#decode when processing crafted LZ4 frames. A remote attacker can send a specially crafted compressed frame header and payload to cause a denial of service.

On the compressed path, header fields are trusted for sizing, allowing a small request to force allocation of a much larger ByteBuf.


8) Prototype pollution (CVE-ID: CVE-2026-42264)

CWE-ID: CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes (\'Prototype Pollution\')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to inject credentials and hijack requests.

The vulnerability exists due to improperly controlled modification of object prototype attributes in the HTTP adapter when reading configuration properties via direct property access from polluted prototypes. A remote attacker can pollute Object.prototype through another dependency in the same process to inject credentials and hijack requests.

Exploitation requires prototype pollution by another dependency in the same process, and requests using relative URLs can be redirected to an attacker-controlled server.


9) HTTP response splitting (CVE-ID: CVE-2026-42035)

CWE-ID: CWE-113 - Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to inject arbitrary HTTP headers into outgoing requests.

The vulnerability exists due to improper neutralization of CRLF sequences in HTTP headers in lib/adapters/http.js when processing data payloads in HTTP requests after a polluted object prototype causes plain objects to be treated as FormData instances. A remote attacker can pollute Object.prototype so that an attacker-controlled getHeaders() function is invoked to inject arbitrary HTTP headers into outgoing requests.

Exploitation requires a prototype pollution primitive somewhere in the application's dependency chain and the application must use Axios to send requests with a data payload such as POST, PUT, or PATCH.


10) Prototype pollution (CVE-ID: CVE-2026-42033)

CWE-ID: CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes (\'Prototype Pollution\')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to tamper with JSON responses and disclose sensitive information.

The vulnerability exists due to prototype pollution in parseReviver handling in the transformResponse functionality when processing JSON responses in a process where Object.prototype has been polluted by a co-dependency. A remote attacker can pollute Object.prototype.parseReviver to tamper with JSON responses and disclose sensitive information.

This issue affects the parseReviver gadget and requires a separate source of prototype pollution in the same process.


11) HTTP response splitting (CVE-ID: CVE-2026-40175)

CWE-ID: CWE-113 - Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')

CVSSv4: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to perform HTTP splitting attacks.

The vulnerability exists due to software does not correclty process CRLF character sequences. A remote attacker can send specially crafted request containing CRLF sequence and make the application to send a split HTTP response.

Successful exploitation of the vulnerability may allow an attacker perform cache poisoning attack.


12) Prototype pollution (CVE-ID: CVE-2026-46625)

CWE-ID: CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes (\'Prototype Pollution\')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to inject cookie attributes.

The vulnerability exists due to improperly controlled modification of object prototype attributes in the assign() helper when processing a JSON-derived attributes object. A remote attacker can supply a specially crafted object containing a __proto__ property to inject cookie attributes.

This issue affects applications that pass attacker-influenced JSON-derived objects as the attributes argument to Cookies.set, Cookies.remove, Cookies.withAttributes, or Cookies.withConverter.


13) Inefficient regular expression complexity (CVE-ID: CVE-2026-33671)

CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper input validation in extglob quantifier handling when parsing input. A remote attacker can send a specially crafted pattern to cause a denial of service.


14) Prototype pollution (CVE-ID: CVE-2026-44495)

CWE-ID: CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes (\'Prototype Pollution\')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to execute injected code in the Axios request-processing context, disclose sensitive information, tamper with response data, or cause a denial of service.

The vulnerability exists due to improperly controlled modification of object prototype attributes in Axios request config processing and response transformation when handling requests after Object.prototype has been polluted with a crafted transformResponse value. A remote attacker can pollute Object.prototype.transformResponse through a separate prototype-pollution primitive to execute injected code in the Axios request-processing context, disclose sensitive information, tamper with response data, or cause a denial of service.

Exploitation requires a separate vulnerability or equivalent capability to control Object.prototype in the same JavaScript process or browser context before Axios merges or validates the request config. Browser and Node usage can both be affected.


15) Prototype pollution (CVE-ID: CVE-2026-42041)

CWE-ID: CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes (\'Prototype Pollution\')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to bypass application-level authentication checks and suppress HTTP error handling.

The vulnerability exists due to improperly controlled modification of object prototype attributes ('prototype pollution') in lib/core/mergeConfig.js and lib/core/settle.js when merging request configuration after Object.prototype has been polluted with a crafted validateStatus property. A remote attacker can pollute Object.prototype.validateStatus with a function that always returns true to bypass application-level authentication checks and suppress HTTP error handling.

Exploitation requires chaining with an existing prototype pollution condition elsewhere in the application stack.


16) Insertion of Sensitive Information Into Sent Data (CVE-ID: CVE-2026-44487)

CWE-ID: CWE-201 - Insertion of Sensitive Information Into Sent Data

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to insertion of sensitive information into sent data in the Node.js HTTP adapter when following an HTTP-to-HTTPS redirect from a proxied request to a direct request. A remote attacker can trigger a crafted redirect flow to disclose sensitive information.

Only Node.js requests using the HTTP adapter are affected, and exploitation requires redirects to be followed and proxy credentials to be configured for the initial HTTP request but not for the redirected HTTPS request.


17) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2026-44488)

CWE-ID: CWE-770 - Allocation of Resources Without Limits or Throttling

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to allocation of resources without limits or throttling in the fetch adapter when processing requests and responses with configured finite size limits. A remote attacker can supply an oversized response, a large data: URL, or an oversized request body to cause a denial of service.

The issue affects server-side usage where applications rely on maxContentLength or maxBodyLength being enforced by the fetch adapter.


18) Information disclosure (CVE-ID: CVE-2026-44486)

CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to improper handling of sensitive headers in the Node.js HTTP adapter in lib/adapters/http.js when following redirects after proxy settings are re-evaluated from an authenticated proxy to a direct connection. A remote attacker can cause the application to follow a crafted redirect so that proxy credentials are sent to the redirect target to disclose sensitive information.

Only the Node.js HTTP adapter is affected, and exploitation requires automatic redirects to be enabled with an authenticated proxy configuration.


19) Server-Side Request Forgery (SSRF) (CVE-ID: CVE-2026-44492)

CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Green


The disclosed vulnerability allows a remote attacker to perform SSRF attacks.

The vulnerability exists due to the "shouldBypassProxy" does not normalise IPv4-mapped IPv6 addresses. A remote attacker can send a specially crafted HTTP request and trick the application to initiate requests to arbitrary systems.

Successful exploitation of this vulnerability may allow a remote attacker gain access to sensitive data, located in the local network or send malicious requests to other servers from the vulnerable system.


20) Prototype pollution (CVE-ID: CVE-2026-44494)

CWE-ID: CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes (\'Prototype Pollution\')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P/U:Amber


The vulnerability allows a remote attacker to execute arbitrary JavaScript code.

The vulnerability exists due to improper input validation in config.proxy. A remote attacker can pass specially crafted input to the application and perform a man-in-the-middle (MitM) attack, which can result in information disclosure or data manipulation.


21) CRLF injection (CVE-ID: CVE-2026-12143)

CWE-ID: CWE-93 - Improper Neutralization of CRLF Sequences ('CRLF Injection')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to inject arbitrary data in server response.

The vulnerability exists due to insufficient validation of attacker-supplied data. A remote attacker can pass specially crafted data to the application containing CR-LF characters and modify application behavior.


22) Inefficient regular expression complexity (CVE-ID: CVE-2026-44496)

CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to inefficient regular expression complexity in lib/helpers/cookies.js read(name) when processing an attacker-controlled XSRF cookie name while reading document.cookie. A remote attacker can supply a crafted cookie name containing regex metacharacters to cause a denial of service.

The issue affects standard browser environments and can freeze the affected browser tab while axios prepares a request. Applications are affected only when attacker-controlled data reaches the XSRF cookie name configuration or an unsafe direct call to the internal cookie helper.


23) Resource exhaustion (CVE-ID: CVE-2026-34043)

CWE-ID: CWE-400 - Resource exhaustion

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to uncontrolled resource consumption in the serialize() function when serializing a specially crafted array-like object. A remote attacker can supply a crafted array-like object to cause a denial of service.

Exploitation can cause 100% CPU usage and the process may hang indefinitely.


24) Inconsistent interpretation of HTTP requests (CVE-ID: CVE-2026-2332)

CWE-ID: CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to inject arbitrary HTTP requests.

The vulnerability exists due to inconsistent interpretation of HTTP requests in the chunked transfer encoding extension parser when parsing quoted strings in HTTP/1.1 chunked transfer encoding extension values. A remote attacker can send a specially crafted chunked HTTP request to inject arbitrary HTTP requests.

The issue occurs because CRLF sequences inside quoted strings are treated as chunk header terminators instead of parsing errors.


Remediation

Install update from vendor's website.