GHSA-xpp7-93x6-v29m
HIGHGHSA-xpp7-93x6-v29m is a high-severity (CVSS 7.5) Cross-site Scripting (XSS) vulnerability in @tryghost/activitypub. O3 Security confirms whether GHSA-xpp7-93x6-v29m is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
XSS in Ghost's ActivityPub client
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
@tryghost/activitypubnpmDescription
Impact
The ActivityPub client in Ghost was vulnerable to JavaScript injection on posts shared by a maliciously customised ActivityPub server.
Vulnerable Versions
This vulnerability is present in the @tryghost/activitypub package up to v3.0.8. All prior versions are also affected.
Patches
@tryghost/activitypub v3.1.0 contains a fix for this issue and is also automatically fetched by Ghost.
References
Ghost thanks Brad Geesaman, Ghost Security for disclosing this vulnerability responsibly.
For more information
If you have any questions or comments about this advisory, email Ghost at [email protected].
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @tryghost/activitypub | all versions | 3.1.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @tryghost/activitypub. 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 @tryghost/activitypub to 3.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xpp7-93x6-v29m 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-xpp7-93x6-v29m 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-xpp7-93x6-v29m. 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-xpp7-93x6-v29m in your dependencies?
O3 detects GHSA-xpp7-93x6-v29m across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.