How severe is GHSA-626q-v9j4-mcp4?

GHSA-626q-v9j4-mcp4 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-626q-v9j4-mcp4?

GHSA-626q-v9j4-mcp4 affects the following packages: openzeppelin-cairo-contracts (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-626q-v9j4-mcp4?

Update openzeppelin-cairo-contracts to 0.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-626q-v9j4-mcp4 is resolved across your whole dependency graph.

How do I detect GHSA-626q-v9j4-mcp4 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openzeppelin-cairo-contracts. 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.

How do I mitigate GHSA-626q-v9j4-mcp4 if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-626q-v9j4-mcp4?

O3 pinpoints whether GHSA-626q-v9j4-mcp4 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-626q-v9j4-mcp4 actively exploited in the wild?

No public exploit code has been indexed for GHSA-626q-v9j4-mcp4 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-626q-v9j4-mcp4?

GHSA-626q-v9j4-mcp4 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 12th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was GHSA-626q-v9j4-mcp4 published, and has it been updated?

GHSA-626q-v9j4-mcp4 was published on February 2, 2023 and was last updated on February 22, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

GHSA-626q-v9j4-mcp4

MEDIUM

OpenZeppelin Contracts contains Improper Verification of Cryptographic Signature

Also known asCVE-2023-23940PYSEC-2023-39

Published

Feb 2, 2023

Updated

Feb 22, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk12th percentile+0.16%

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

1 pkg affected

🐍openzeppelin-cairo-contracts

Real-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

Cause

is_valid_eth_signature is missing a call to finalize_keccak after calling verify_eth_signature.

Impact

As a result, any contract using is_valid_eth_signature from the account library (such as the EthAccount preset) is vulnerable to a malicious sequencer. Specifically, the malicious sequencer would be able to bypass signature validation to impersonate an instance of these accounts.

Risk

In order to exploit this vulnerability, it is required to control a sequencer or prover since they're the ones executing the hints, being able to inject incorrect keccak results.

Today StarkWare is the only party running both a prover or a sequencer, greatly reducing the risk of exploit.

Patches

The issue has been patched in 0.6.1.

For more information

If you have any questions or comments about this advisory:

Open an issue in the Contracts for Cairo repository
Email us at [email protected]

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`openzeppelin-cairo-contracts`	≥ 0.2.0&&< 0.6.1	0.6.1

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openzeppelin-cairo-contracts. 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 openzeppelin-cairo-contracts to 0.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-626q-v9j4-mcp4 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-626q-v9j4-mcp4 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-626q-v9j4-mcp4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Cause `is_valid_eth_signature` is missing a call to `finalize_keccak` after calling `verify_eth_signature`. ### Impact As a result, any contract using `is_valid_eth_signature` from the account library (such as the `EthAccount` preset) is vulnerable to a malicious sequencer. Specifically, the malicious sequencer would be able to bypass signature validation to impersonate an instance of these accounts. ### Risk In order to exploit this vulnerability, it is required to control a sequencer or prover since they're the ones executing the hints, being able to inject incorrect keccak results.

O3 Security · Impact-Aware SCA

Is GHSA-626q-v9j4-mcp4 in your dependencies?

O3 detects GHSA-626q-v9j4-mcp4 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works