CVE-2026-44167 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.
phpseclib: CVE-2024-27355 mitigation bypass — OID amplification DoS in ASN1::decodeOID()
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 CVE-2026-44167.
EPSS Exploitation Probability
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.
How urgent is this, really
CVE-2026-44167 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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
phpseclib is a PHP secure communications library. Prior to 1.0.29, 2.0.54, and 3.0.52, anyone loading untrusted ASN1 files (eg. X509 certificates, RSA PKCS8 private or public keys, etc). This is a bypass of CVE-2024-27355. This vulnerability is fixed in 1.0.29, 2.0.54, and 3.0.52.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | phpseclib/phpseclib | ≥ 0.1.1&&< 1.0.29 | 1.0.29composer require phpseclib/phpseclib:^1.0.29 |
| 🐘Packagist | phpseclib/phpseclib | ≥ 2.0.0&&< 2.0.54 | 2.0.54composer require phpseclib/phpseclib:^2.0.54 |
| 🐘Packagist | phpseclib/phpseclib | ≥ 3.0.0&&< 3.0.52 | 3.0.52composer require phpseclib/phpseclib:^3.0.52 |
Detection & 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 1.0.29 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44167 is resolved across your whole dependency graph.
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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-44167 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-44167. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-44167 in your dependencies?
O3 Security finds CVE-2026-44167 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.