SB2026092430 - Multiple vulnerabilities in IBM Optim
Published: September 24, 2026 Updated: September 30, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 vulnerabilities.
1) Input validation error (CVE-ID: CVE-2026-27135)
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 missing state validation in the nghttp2 session handling logic when processing malformed frames after session termination has been initiated. A remote attacker can send specially crafted frames to cause a denial of service.
For PRIORITY_UPDATE and ALTSVC frames, the affected extension types must be explicitly enabled. Builds with assertions disabled may not crash under the same conditions.
2) Improper input validation (CVE-ID: CVE-2026-4424)
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:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to improper input validation in libarchive when parsing input. A remote attacker can supply specially crafted archive data to disclose sensitive information.
3) Infinite loop (CVE-ID: CVE-2026-4111)
CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L]
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to infinite loop in the RAR5 decompression implementation. A remote attacker can pass specially crafted compressed data to the application, consume all available system resources and cause denial of service conditions.
Remediation
Install update from vendor's website.