GHSA-8qff-qr5q-5pr8
OpenPGP.js's message signature verification can be spoofed
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
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
openpgpnpmDescription
Impact
A maliciously modified message can be passed to either openpgp.verify or openpgp.decrypt, causing these functions to return a valid signature verification result while returning data that was not actually signed.
This flaw allows signature verifications of inline (non-detached) signed messages (using openpgp.verify) and signed-and-encrypted messages (using openpgp.decrypt with verificationKeys) to be spoofed, since both functions return extracted data that may not match the data that was originally signed. Detached signature verifications are not affected, as no signed data is returned in that case.
In order to spoof a message, the attacker needs a single valid message signature (inline or detached) as well as the plaintext data that was legitimately signed, and can then construct an inline-signed message or signed-and-encrypted message with any data of the attacker's choice, which will appear as legitimately signed by affected versions of OpenPGP.js.
In other words. any inline-signed message can be modified to return any other data (while still indicating that the signature was valid), and the same is true for signed+encrypted messages if the attacker can obtain a valid signature and encrypt a new message (of the attacker's choice) together with that signature.
Both OpenPGP.js v6 and v5 are affected. OpenPGP.js v4 is not affected.
Patches
The issue has been patched in versions 5.11.3 and 6.1.1.
Workarounds
- When verifying inline-signed messages, extract the message and signature(s) from the message returned by
openpgp.readMessage, and verify the(/each) signature as a detached signature by passing the signature and a new message containing only the data (created usingopenpgp.createMessage) toopenpgp.verify. - When decrypting and verifying signed+encrypted messages, decrypt and verify the message in two steps, by first calling
openpgp.decryptwithoutverificationKeys, and then passing the returned signature(s) and a new message containing the decrypted data (created usingopenpgp.createMessage) toopenpgp.verify.
Acknowledgements
We would like to thank:
- Edoardo Geraci and Thomas Rinsma of Codean Labs for finding and reporting this vulnerability
- The Sovereign Tech Agency for sponsoring the OpenPGP.js bug bounty program
- YesWeHack for hosting the OpenPGP.js bug bounty program
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | openpgp | ≥ 5.0.1&&< 5.11.3 | 5.11.3 |
| 📦npm | openpgp | ≥ 6.0.0-alpha.0&&< 6.1.1 | 6.1.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openpgp. 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 openpgp to 5.11.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8qff-qr5q-5pr8 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-8qff-qr5q-5pr8 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-8qff-qr5q-5pr8. 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-8qff-qr5q-5pr8 in your dependencies?
O3 detects GHSA-8qff-qr5q-5pr8 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.