SB2026080311 - Red Hat Enterprise Linux 9 update for osbuild-composer
Published: August 3, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 6 vulnerabilities.
1) Improper Certificate Validation (CVE-ID: CVE-2025-68121)
CWE-ID: CWE-295 - Improper Certificate Validation
CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to improper certificate validation within HTTP/3 connections. A remote attacker can cause cause a client to resume a session with a server that it would not have resumed with during the initial handshake
2) Input validation error (CVE-ID: CVE-2026-25679)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 6.9 [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]
The vulnerability allows a remote attacker to bypass URL parsing validation and potentially access unintended resources.
The vulnerability exists due to insufficient validation in net/url.Parse when handling IPv6 literals not located at the start of the host component. A remote attacker can send a specially crafted URL with an IPv6 literal preceded by garbage characters to bypass proper parsing and potentially redirect requests.
This issue affects any application using net/url.Parse to process untrusted URLs. The incorrect parsing may lead to misrouting or injection of unintended host components.
3) Input validation error (CVE-ID: CVE-2026-32281)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: 8.7 [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]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper input validation in Certificate.Verify in crypto/x509 when validating certificate chains containing a very large number of policy mappings. A remote attacker can present a specially crafted certificate chain to cause a denial of service.
This only affects validation of otherwise trusted certificate chains issued by a root CA in the VerifyOptions.Roots CertPool or in the system certificate pool.
4) 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: 5.7 [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]
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.
5) Dependency on vulnerable third-party component (CVE-ID: CVE-2026-32283)
CWE-ID: CWE-1395 - Dependency on Vulnerable Third-Party Component
CVSSv4: 8.7 [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]
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.
6) Resource exhaustion (CVE-ID: CVE-2026-32280)
CWE-ID: CWE-400 - Resource exhaustion
CVSSv4: 8.7 [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]
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.