USN-8830-1: phpseclib vulnerabilities
Ubuntu fixes three phpseclib flaws covering AES timing leaks, SSH MAC comparison, and ASN.1 denial of service.
USN-8830-1 fixes three phpseclib vulnerabilities. CVE-2026-32935 is non-constant-time AES-CBC padding validation that may expose sensitive information, and CVE-2026-40194 is a non-constant-time SSH packet MAC comparison with the same potential impact. CVE-2026-44167 does not limit ASN.1 object identifier lengths, which can exhaust resources and cause denial of service. Active exploitation is not reported.
- CVE-2026-32935 may leak data via non-constant-time AES-CBC padding checks
- CVE-2026-40194 uses a non-constant-time SSH packet MAC comparison
- CVE-2026-44167 can exhaust resources through unbounded ASN.1 identifiers
Vulnerabilities mentioned
All| CVE | Vulnerability | CVSS | EPSS | Signals | Published |
|---|---|---|---|---|---|
| CVE-2026-32935 | phpseclib is a PHP secure communications library | 8.2 | <1% | ||
| CVE-2026-40194 | phpseclib is a PHP secure communications library | 3.7 | <1% | ||
| CVE-2026-44167 | phpseclib is a PHP secure communications library | 7.5 | <1% |
From the original article
It was discovered that phpseclib did not perform constant-time padding validation when using AES in CBC mode. A remote attacker could possibly use this issue to obtain sensitive information. (CVE-2026-32935) It was discovered that phpseclib did not use a constant-time comparison when validating SSH packet authentication codes.
ubuntu.com
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