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GHSA-2q89-485c-9j2x

MEDIUM

Improper random reading in CIRCL

Also known asCVE-2023-1732GO-2023-1765
Published
May 11, 2023
Updated
Mar 13, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk30th percentile-0.03%
0.00%0.30%0.61%0.92%0.2%0.4%Dec 25Apr 26Jun 26

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
🐹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

Impact

When sampling randomness for a shared secret, the implementation of Kyber and FrodoKEM, did not check whether crypto/rand.Read() returns an error. In rare deployment cases (error thrown by the Read() function), this could lead to a predictable shared secret.

The tkn20 and blindrsa components did not check whether enough randomness was returned from the user provided randomness source. Typically the user provides crypto/rand.Reader, which in the vast majority of cases will always return the right number random bytes. In the cases where it does not, or the user provides a source that does not, the blinding for blindrsa is weak and integrity of the plaintext is not ensured in tkn20.

Patches

The fix was introduced in CIRCL v. 1.3.3

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/cloudflare/circlall versions1.3.3

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. 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.

  2. Fix

    Update github.com/cloudflare/circl to 1.3.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-2q89-485c-9j2x 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 pinpoints whether GHSA-2q89-485c-9j2x 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-2q89-485c-9j2x. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact When sampling randomness for a shared secret, the implementation of Kyber and FrodoKEM, did not check whether `crypto/rand.Read()` returns an error. In rare deployment cases (error thrown by the `Read()` function), this could lead to a predictable shared secret. The tkn20 and blindrsa components did not check whether enough randomness was returned from the user provided randomness source. Typically the user provides `crypto/rand.Reader`, which in the vast majority of cases will always return the right number random bytes. In the cases where it does not, or the user provides a sourc
O3 Security · Impact-Aware SCA

Is GHSA-2q89-485c-9j2x in your dependencies?

O3 detects GHSA-2q89-485c-9j2x across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

GHSA-2q89-485c-9j2x: Improper random reading in CIRCL (Medium 5… | O3 Security