GHSA-fg86-4c2r-7wxw is a critical-severity (CVSS 9.8) Deserialization of Untrusted Data vulnerability in torrentpier/torrentpier. A fix is available for torrentpier/torrentpier — see the affected versions and patch details below.
TorrentPier Deserialization of Untrusted Data vulnerability
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-fg86-4c2r-7wxw.
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
GHSA-fg86-4c2r-7wxw 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 379,145 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
torrentpier/torrentpierReal-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
TorrentPier is an open source BitTorrent Public/Private tracker engine, written in php. In torrentpier/library/includes/functions.php, get_tracks() uses the unsafe native PHP serialization format to deserialize user-controlled cookies. One can use phpggc and the chain Guzzle/FW1 to write PHP code to an arbitrary file, and execute commands on the system. For instance, the cookie bb_t will be deserialized when browsing to viewforum.php. This issue has been addressed in commit ed37e6e52 which is expected to be included in release version 2.4.4. Users are advised to upgrade as soon as the new release is available. There are no known workarounds for this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | torrentpier/torrentpier | all versions | 2.4.4composer require torrentpier/torrentpier:^2.4.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for torrentpier/torrentpier, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update torrentpier/torrentpier to 2.4.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fg86-4c2r-7wxw 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 GHSA-fg86-4c2r-7wxw can be triaged on real exposure rather than presence alone.
Tailored to GHSA-fg86-4c2r-7wxw. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-fg86-4c2r-7wxw in your dependencies?
O3 Security finds GHSA-fg86-4c2r-7wxw across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.