GHSA-f2qx-66wf-wvvx is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in phpseclib/phpseclib. A fix is available for phpseclib/phpseclib — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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 GHSA-f2qx-66wf-wvvx.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
phpseclib/phpseclib🐘phpseclib/phpseclib🐘phpseclib/phpseclibReal-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
Impact
Any application using that loads untrusted ASN1 files (eg. X509 certificates, RSA PKCS8 private or public keys, etc).
Patches
https://github.com/phpseclib/phpseclib/commit/e32531001b4d62c66c3d824ccef54ffad835eb59
Workarounds
No.
Resources
https://github.com/phpseclib/phpseclib/commit/e32531001b4d62c66c3d824ccef54ffad835eb59 https://www.usenix.org/system/files/conference/usenixsecurity25/sec25cycle1-prepub-599-shi-bing.pdf
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | phpseclib/phpseclib | ≥ 2.0.0&&< 2.0.47 | 2.0.47composer require phpseclib/phpseclib:^2.0.47 |
| 🐘Packagist | phpseclib/phpseclib | ≥ 3.0.0&&< 3.0.36 | 3.0.36composer require phpseclib/phpseclib:^3.0.36 |
| 🐘Packagist | phpseclib/phpseclib | ≥ 0.1.1&&< 1.0.23 | 1.0.23composer require phpseclib/phpseclib:^1.0.23 |
Affected Products
debian linuxdebianphpseclibphpseclibDetection & mitigation playbook
Open-source dependencyDetect
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.
Fix
Update phpseclib/phpseclib to 2.0.47 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f2qx-66wf-wvvx is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
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.
Frequently Asked Questions
Is GHSA-f2qx-66wf-wvvx in your dependencies?
Find it across Packagist, including transitive dependencies.