GHSA-xqqc-c5gw-c5r5 is a medium-severity (CVSS 5.4) CWE-347 vulnerability in tendermint-light-client-verifier. O3 Security confirms whether GHSA-xqqc-c5gw-c5r5 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Tendermint light client verification not taking into account chain ID
Real-World Exposure
tendermint-light-client-verifier🦀tendermint-light-client🦀tendermint-light-client-jsReal-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
Impact
Anyone using the tendermint-light-client and related packages to perform light client verification (e.g. IBC-rs, Hermes).
At present, the light client does not check that the chain IDs of the trusted and untrusted headers match, resulting in a possible attack vector where someone who finds a header from an untrusted chain that satisfies all other verification conditions (e.g. enough overlapping validator signatures) could fool a light client.
The attack vector is currently theoretical, and no proof-of-concept exists yet to exploit it on live networks.
Patches
Users of the light client-related crates can currently upgrade to v0.28.0.
Workarounds
None
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | tendermint-light-client-verifier | all versions | 0.28.0 |
| 🦀crates.io | tendermint-light-client | all versions | 0.28.0 |
| 🦀crates.io | tendermint-light-client-js | all versions | 0.28.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tendermint-light-client-verifier. 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 tendermint-light-client-verifier to 0.28.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xqqc-c5gw-c5r5 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-xqqc-c5gw-c5r5 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-xqqc-c5gw-c5r5. 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-xqqc-c5gw-c5r5 in your dependencies?
O3 detects GHSA-xqqc-c5gw-c5r5 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.