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CVE-2026-32935 phpseclib/phpseclib

Fix: phpseclib/phpseclib@ccc21ae

CVE-2026-32935 is a CWE-208 vulnerability in phpseclib/phpseclib. A fix is available for phpseclib/phpseclib — see the affected versions and patch details below.

phpseclib's AES-CBC unpadding susceptible to padding oracle timing attack

Also known asGHSA-94g3-g5v7-q4jg
Published
Mar 20, 2026
Updated
Aug 12, 2026
Affected
3 pkgs
Patched
3 / 3
Exploits
None indexed
Exploitation data as of Sep 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-32935.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs31th percentile — riskier than 31% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

3 pkgs affected
🐘phpseclib/phpseclib🐘phpseclib/phpseclib🐘phpseclib/phpseclib

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

phpseclib is a PHP secure communications library. Projects using versions 0.1.1 through 1.0.26, 2.0.0 through 2.0.51, and 3.0.0 through 3.0.49 are vulnerable to a to padding oracle timing attack when using AES in CBC mode. This issue has been fixed in versions 1.0.27, 2.0.52 and 3.0.50.

Affected Packages

3 total 3 fixed
EcosystemPackageVulnerable rangeFix
🐘Packagistphpseclib/phpseclib3.0.0&&< 3.0.503.0.50composer require phpseclib/phpseclib:^3.0.50
🐘Packagistphpseclib/phpseclib2.0.0&&< 2.0.522.0.52composer require phpseclib/phpseclib:^2.0.52
🐘Packagistphpseclib/phpseclib0.1.1&&< 1.0.271.0.27composer require phpseclib/phpseclib:^1.0.27

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for phpseclib/phpseclib, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update phpseclib/phpseclib to 3.0.50 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-32935 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-32935 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-32935. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

UbuntuMEDIUM

Frequently Asked Questions

phpseclib is a PHP secure communications library. Projects using versions 0.1.1 through 1.0.26, 2.0.0 through 2.0.51, and 3.0.0 through 3.0.49 are vulnerable to a to padding oracle timing attack when using AES in CBC mode. This issue has been fixed in versions 1.0.27, 2.0.52 and 3.0.50.
O3 Security · Impact-Aware SCA

Is CVE-2026-32935 in your dependencies?

O3 Security finds CVE-2026-32935 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

CVE-2026-32935: phpseclib/phpseclib | O3 Security