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
pollbotReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
(From https://bugzilla.mozilla.org/show_bug.cgi?id=1753838)
Summary: There was an open redirection vulnerability in the path of:
https://pollbot.services.mozilla.com/ and https://pollbot.stage.mozaws.net/
Description: An attacker can redirect anyone to malicious sites.
Steps To Reproduce: Type in this URL:
https://pollbot.services.mozilla.com/%0a/evil.com/
It redirects to that website
evil.com
evil.com was used as an example but this could be any website. Note, the /%0a/ and trailing / are required.
Supporting Material/References: https://cheatsheetseries.owasp.org/cheatsheets/Unvalidated_Redirects_and_Forwards_Cheat_Sheet.html
Impact
Attackers can serve malicious websites that steal passwords or download ransomware to their victims machine due to a redirect and there are a heap of other attack vectors.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pollbot | all versions | 1.4.6 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pollbot. 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.
Fix
Update pollbot to 1.4.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vg27-hr3v-3cqv 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 pinpoints whether GHSA-vg27-hr3v-3cqv 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 GHSA-vg27-hr3v-3cqv. 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-vg27-hr3v-3cqv in your dependencies?
O3 detects GHSA-vg27-hr3v-3cqv across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.