SB20260731137 - Red Hat Enterprise Linux 8 update for osbuild-composer



SB20260731137 - Red Hat Enterprise Linux 8 update for osbuild-composer

Published: July 31, 2026

Security Bulletin ID SB20260731137
CSH Severity
High
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

High 20% Medium 60% Low 20%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 vulnerabilities.


1) Improper Authorization (CVE-ID: CVE-2026-33186)

CWE-ID: CWE-285 - Improper Authorization

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


The vulnerability allows a remote attacker to gain access to bypass authorization.

The vulnerability exists due to authorization bypass resulting from improper input validation of the HTTP/2 `:path` pseudo-header. A remote attacker can send raw HTTP/2 frames with malformed `:path` headers directly to the gRPC server to bypass authorization.


2) Improper input validation (CVE-ID: CVE-2026-34986)

CWE-ID: CWE-20 - Improper input validation

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 JWE decryption in key_wrap.go when processing a JWE object with a key wrapping algorithm and an empty encrypted_key field. A remote attacker can send a specially crafted JWE object to cause a denial of service.

The issue is reachable through ParseEncrypted(), ParseEncryptedJSON(), or ParseEncryptedCompact() followed by Decrypt(), and applications are affected only if accepted key algorithms include key wrapping algorithms.


3) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: CVE-2026-32282)

CWE-ID: CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition

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


The vulnerability allows a local user to modify file permissions outside the intended root directory.

The vulnerability exists due to improper access control in Root.Chmod and internal/syscall/unix Fchmodat when handling a chmod operation on Linux. A local user can replace the target with a symlink during the check-and-operation window to modify file permissions outside the intended root directory.

Exploitation requires a race condition in which the target is swapped with a symlink while the chmod operation is in progress.


4) Dependency on vulnerable third-party component (CVE-ID: CVE-2026-32283)

CWE-ID: CWE-1395 - Dependency on Vulnerable Third-Party Component

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 dependency on a vulnerable third-party component in the Go standard library used by Fleet Server when handling network input. A remote attacker can send a specially crafted payload to cause a denial of service.

All configurations are affected.


5) Resource exhaustion (CVE-ID: CVE-2026-32280)

CWE-ID: CWE-400 - Resource exhaustion

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 the Certificate.Verify chain-building logic in crypto/x509 when processing a large number of intermediate certificates supplied through VerifyOptions.Intermediates. A remote attacker can provide a large number of intermediate certificates to cause a denial of service.

This affects both direct users of crypto/x509 and users of crypto/tls.


Remediation

Install update from vendor's website.