GHSA-xchq-w5r3-4wg3
MEDIUMvyper performs incorrect topic logging in raw_log
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
vyperReal-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
Summary
Incorrect values can be logged when raw_log builtin is called with memory or storage arguments to be used as topics.
A contract search was performed and no vulnerable contracts were found in production. In particular, no uses of raw_log() were found at all in production; it is apparently not a well-known function.
Details
The build_IR function of the RawLog class fails to properly unwrap the variables provided as topics. Consequently, incorrect values are logged as topics.
PoC
x: bytes32
@external
def f():
self.x = 0x1234567890123456789012345678901234567890123456789012345678901234
raw_log([self.x], b"") # LOG1(offset:0x60, size:0x00, topic1:0x00)
y: bytes32 = 0x1234567890123456789012345678901234567890123456789012345678901234
raw_log([y], b"") # LOG1(offset:0x80, size:0x00, topic1:0x40)
Patches
Fixed in https://github.com/vyperlang/vyper/pull/3977.
Impact
Incorrect values can be logged which may result in unexpected behavior in client-side applications relying on these logs.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | vyper | all versions | 0.4.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vyper. 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 vyper to 0.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xchq-w5r3-4wg3 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-xchq-w5r3-4wg3 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-xchq-w5r3-4wg3. 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-xchq-w5r3-4wg3 in your dependencies?
O3 detects GHSA-xchq-w5r3-4wg3 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.