CVE-2025-25194
MEDIUMServer-Side Request Forgery (SSRF) in activitypub_federation
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.
Blast Radius
activitypub_federationReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Lemmy, a link aggregator and forum for the fediverse, is vulnerable to server-side request forgery via a dependency on activitypub_federation, a framework for ActivityPub federation in Rust. This vulnerability, which is present in versions 0.6.2 and prior of activitypub_federation and versions 0.19.8 and prior of Lemmy, allows a user to bypass any predefined hardcoded URL path or security anti-Localhost mechanism and perform an arbitrary GET request to any Host, Port and URL using a Webfinger Request. As of time of publication, a fix has not been made available.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | activitypub_federation | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for activitypub_federation. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of activitypub_federation has shipped for CVE-2025-25194 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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 pinpoints whether CVE-2025-25194 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-25194. 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-2025-25194 in your dependencies?
O3 detects CVE-2025-25194 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.