SB2026022859 - Debian update for thunderbird

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Main Vulnerability Database SB2026022859

SB2026022859 - Debian update for thunderbird

Published: February 28, 2026

Security Bulletin ID SB2026022859
CSH Severity
High
Patch available
YES
Number of vulnerabilities 36
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 64% Medium 14% Low 22%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 36 vulnerabilities.


1) NULL pointer dereference (CVE-ID: CVE-2026-2785)

CWE-ID: CWE-476 - NULL Pointer Dereference

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


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in the JavaScript Engine component. A remote attacker can trick the victim into visiting a specially crafted website and crash the browser. 


2) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2026-2777)

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

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


The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to application does not properly impose security restrictions in the Messaging System component. A remote attacker can trick the victim into visiting a specially crafted website and execute arbitrary code on the system.


3) Buffer overflow (CVE-ID: CVE-2026-2778)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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 on the target system.

The vulnerability exists due to a boundary error when processing HTML code in the DOM: Core & HTML component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.


4) Buffer overflow (CVE-ID: CVE-2026-2779)

CWE-ID: CWE-119 - Memory corruption

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


The vulnerability allows a remote attacker to crash the browser.

The vulnerability exists due to a boundary error when processing HTML content in the Networking: JAR component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and crash the browser.


5) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2026-2780)

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

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


The vulnerability allows a remote attacker to escalate privileges on the system.

The vulnerability exists due to application does not properly impose security restrictions in the Netmonitor component. A remote attacker can escalate privileges on the system.


6) Integer overflow (CVE-ID: CVE-2026-2781)

CWE-ID: CWE-190 - Integer overflow

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


The vulnerability allows a remote attacker to crash the browser.

The vulnerability exists due to integer overflow in the Libraries component in NSS. A remote attacker can trick the victim into visiting a specially crafted website, trigger an integer overflow and crash the browser.


7) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2026-2782)

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

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


The vulnerability allows a remote attacker to escalate privileges on the system.

The vulnerability exists due to application does not properly impose security restrictions in the Netmonitor component. A remote attacker can escalate privileges on the system.


8) Information disclosure (CVE-ID: CVE-2026-2783)

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:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to JIT miscompilation in the JavaScript Engine: JIT component. A remote attacker can gain unauthorized access to sensitive information.


9) Protection mechanism failure (CVE-ID: CVE-2026-2784)

CWE-ID: CWE-693 - Protection Mechanism Failure

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


The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to insufficient implementation of security measures in the DOM: Security component. An attacker can bypass implemented security restrictions.


10) Buffer overflow (CVE-ID: CVE-2026-2776)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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 on the target system.

The vulnerability exists due to a boundary error in the Telemetry component in External Software. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption to bypass sandbox restrictions and execute arbitrary code on the target system.


11) Use-after-free (CVE-ID: CVE-2026-2786)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to crash the browser.

The vulnerability exists due to a use-after-free error in the JavaScript Engine component. A remote attacker can trick the victim into visiting a specially crafted website and crash the browser. 


12) Use-after-free (CVE-ID: CVE-2026-2787)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to crash the browser.

The vulnerability exists due to a use-after-free error in the DOM: Window and Location component. A remote attacker can trick the victim into visiting a specially crafted webpage and crash the browser. 


13) Buffer overflow (CVE-ID: CVE-2026-2788)

CWE-ID: CWE-119 - Memory corruption

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


The vulnerability allows a remote attacker to crash the browser

The vulnerability exists due to a boundary error in the Audio/Video: GMP component. A remote attacker can trick the victim into visiting a specially crafted website and crash the browser.


14) Use-after-free (CVE-ID: CVE-2026-2789)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to crash the browser.

The vulnerability exists due to a use-after-free error in the Graphics: ImageLib component. A remote attacker can trick the victim into visiting a specially crafted webpage and crash the browser. 


15) Protection mechanism failure (CVE-ID: CVE-2026-2790)

CWE-ID: CWE-693 - Protection Mechanism Failure

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


The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to insufficient implementation of security measures in the Networking: JAR component. An attacker can bypass same-origin policy. 


16) Protection mechanism failure (CVE-ID: CVE-2026-2791)

CWE-ID: CWE-693 - Protection Mechanism Failure

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


The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to insufficient implementation of security measures in the Networking: Cache component. An attacker can bypass implemented security restrictions.


17) Buffer overflow (CVE-ID: CVE-2026-2792)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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 on the target system.

The vulnerability exists due to a boundary error when processing HTML content. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.


18) Buffer overflow (CVE-ID: CVE-2026-2793)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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 on the target system.

The vulnerability exists due to a boundary error when processing HTML content. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.


19) Use-after-free (CVE-ID: CVE-2026-2767)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in the JavaScript: WebAssembly component. A remote attacker can trick the victim into visiting a specially crafted website and execute arbitrary code on the system.


20) Use-after-free (CVE-ID: CVE-2026-2758)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in JavaScript: GC component. A remote attacker can trick the victim into visiting a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.



21) Buffer overflow (CVE-ID: CVE-2026-2759)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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 on the target system.

The vulnerability exists due to a boundary error when processing HTML content in the Graphics: ImageLib component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.


22) Buffer overflow (CVE-ID: CVE-2026-2761)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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 on the target system.

The vulnerability exists due to a boundary error when processing HTML content in in the Graphics: WebRender component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption to bypass sandbox restrictions and execute arbitrary code on the target system.


23) Integer overflow (CVE-ID: CVE-2026-2762)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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 on the target system.

The vulnerability exists due to integer overflow in the JavaScript: Standard Library component. A remote attacker can trick the victim into visiting a specially crafted website, trigger an integer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


24) Use-after-free (CVE-ID: CVE-2026-2763)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in the JavaScript Engine component. A remote attacker can trick the victim into visiting a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.



25) Use-after-free (CVE-ID: CVE-2026-2764)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in the JavaScript Engine: JIT component. A remote attacker can trick the victim into visiting a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.



26) Use-after-free (CVE-ID: CVE-2026-2765)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in the JavaScript Engine component. A remote attacker can trick the victim into visiting a specially crafted website and execute arbitrary code on the system.


27) Use-after-free (CVE-ID: CVE-2026-2766)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in the JavaScript Engine: JIT component. A remote attacker can trick the victim into visiting a specially crafted website and execute arbitrary code on the system.


28) Buffer overflow (CVE-ID: CVE-2026-2757)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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 on the target system.

The vulnerability exists due to a boundary error when processing HTML content in WebRTC: Audio/Video component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


29) Protection mechanism failure (CVE-ID: CVE-2026-2768)

CWE-ID: CWE-693 - Protection Mechanism Failure

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


The vulnerability allows a remote attacker to compromise the affected system.

The vulnerability exists due to insufficient implementation of security measures in the Storage: IndexedDB component. A remote attacker can trick the victim into visiting a specially crafted website and execute arbitrary code on the system.


30) Use-after-free (CVE-ID: CVE-2026-2769)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in the Storage: IndexedDB component. A remote attacker can trick the victim into visiting a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.



31) Use-after-free (CVE-ID: CVE-2026-2770)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in the DOM: Bindings (WebIDL) component. A remote attacker can trick the victim into visiting a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.



32) Improper Neutralization of Special Elements in Output Used by a Downstream Component (CVE-ID: CVE-2026-2771)

CWE-ID: CWE-74 - Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

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


The vulnerability allows a remote attacker to execute arbitrary code on the system.

The vulnerability exists due to improper input validation in the DOM: Core & HTML component. A remote attacker can execute arbitrary JavaScript code in the browser leading to a system compromise. 


33) Use-after-free (CVE-ID: CVE-2026-2772)

CWE-ID: CWE-416 - Use After Free

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


The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in the Audio/Video: Playback component. A remote attacker can trick the victim into visiting a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.



34) Buffer overflow (CVE-ID: CVE-2026-2773)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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 on the target system.

The vulnerability exists due to a boundary error in the Web Audio component. A remote attacker can trick the victim into visiting a specially crafted website, trigger memory corruption and execute arbitrary code on the target system.


35) Integer overflow (CVE-ID: CVE-2026-2774)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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 on the target system.

The vulnerability exists due to integer overflow in the Audio/Video component. A remote attacker can trick the victim into visiting a specially crafted website, trigger an integer overflow and execute arbitrary code on the target system.


36) Protection mechanism failure (CVE-ID: CVE-2026-2775)

CWE-ID: CWE-693 - Protection Mechanism Failure

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


The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to insufficient implementation of security measures in the DOM: HTML Parser component. An attacker can trick the victim into visiting a specially crafted website and compromise the affected system.


Remediation

Install update from vendor's website.

References