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GHSA-q9hv-hpm4-hj6x — circl

Fix: cloudflare/circl#583

GHSA-q9hv-hpm4-hj6x is a CWE-682 vulnerability in github.com/cloudflare/circl. A fix is available for github.com/cloudflare/circl — see the affected versions and patch details below.

CIRCL has an incorrect calculation in secp384r1 CombinedMult

Also known asCVE-2026-1229GO-2026-4550
Published
Feb 25, 2026
Updated
Sep 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 24, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-q9hv-hpm4-hj6x.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs32th percentile — riskier than 32% of all scored CVEsHighest risk

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.

Real-World Exposure

1 pkg affected
🐹github.com/cloudflare/circl

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

The CombinedMult function in the CIRCL ecc/p384 package (secp384r1 curve) produces an incorrect value for specific inputs. The issue is fixed by using complete addition formulas. ECDH and ECDSA signing relying on this curve are not affected.

The bug was fixed in v1.6.3.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/cloudflare/circlall versions1.6.3go get github.com/cloudflare/circl@v1.6.3

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cloudflare/circl, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update github.com/cloudflare/circl to 1.6.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q9hv-hpm4-hj6x is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-q9hv-hpm4-hj6x can be triaged on real exposure rather than presence alone.

Tailored to GHSA-q9hv-hpm4-hj6x. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

The CombinedMult function in the CIRCL ecc/p384 package (secp384r1 curve) produces an incorrect value for specific inputs. The issue is fixed by using complete addition formulas. ECDH and ECDSA signing relying on this curve are not affected. The bug was fixed in **[v1.6.3](https://github.com/cloudflare/circl/releases/tag/v1.6.3)**.
O3 Security · Impact-Aware SCA

Is GHSA-q9hv-hpm4-hj6x in your dependencies?

O3 Security finds GHSA-q9hv-hpm4-hj6x across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-q9hv-hpm4-hj6x: circl | O3 Security