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Not in CISA KEV
HIGH severity

GHSA-w5hq-g745-h8pq uuid

HIGHFix: uuidjs/uuid@32389c8

GHSA-w5hq-g745-h8pq is a high-severity (CVSS 7.5) Out-of-bounds Write vulnerability in uuid. A fix is available for uuid — see the affected versions and patch details below.

uuid: Missing buffer bounds check in v3/v5/v6 when buf is provided

Published
Apr 22, 2026
Updated
Sep 10, 2026
Affected
3 pkgs
Patched
3 / 3
Exploits
None indexed
Exploitation data as of Sep 18, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for GHSA-w5hq-g745-h8pq.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs29th percentile — riskier than 29% 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.

How urgent is this, really

GHSA-w5hq-g745-h8pq plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

3 pkgs affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

79Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream
uuidnpm
259.7Mdownloads / week

Description

Summary

The v3(), v5(), and v6() API methods (not uuid release versions) accept external output buffers but do not reject out-of-range writes (small buf or large offset).
By contrast, v4(), v1(), and v7() API methods explicitly throw RangeError on invalid bounds.

This inconsistency allows silent partial writes into caller-provided buffers.

Affected code

  • src/v35.ts (v3()/v5() path) writes buf[offset + i] without bounds validation.
  • src/v6.ts writes buf[offset + i] without bounds validation.

Reproducible PoC

cd /home/StrawHat/uuid
npm ci
npm run build

node --input-type=module -e "
import {v4,v5,v6} from './dist-node/index.js';
const ns='6ba7b810-9dad-11d1-80b4-00c04fd430c8';
for (const [name,fn] of [
  ['v4()',()=>v4({},new Uint8Array(8),4)],
  ['v5()',()=>v5('x',ns,new Uint8Array(8),4)],
  ['v6()',()=>v6({},new Uint8Array(8),4)],
]) {
  try { fn(); console.log(name,'NO_THROW'); }
  catch(e){ console.log(name,'THREW',e.name); }
}"

Observed:

  • v4() THREW RangeError
  • v5() NO_THROW
  • v6() NO_THROW

Example partial overwrite evidence captured during audit:

same true buf [
  170, 170, 170, 170,
   75, 224, 100,  63
]
v6 [
  187, 187, 187, 187,
   31,  19, 185,  64
]

Security impact

  • Primary: integrity/robustness issue (silent partial output).
  • If an application assumes full UUID writes into preallocated buffers, this can produce malformed/truncated/partially stale identifiers without error.
  • In systems where caller-controlled offsets/buffer sizes are exposed indirectly, this may become a security-relevant logic flaw.

Suggested fix

Add the same guard used by v4()/v1()/v7():

if (offset < 0 || offset + 16 > buf.length) {
  throw new RangeError(`UUID byte range ${offset}:${offset + 15} is out of buffer bounds`);
}

Apply to:

  • src/v35.ts (covers v3() and v5())
  • src/v6.ts

Affected Packages

3 total 3 fixed
EcosystemPackageVulnerable rangeFix
📦npmuuidall versions11.1.1npm install uuid@11.1.1
📦npmuuid12.0.0&&< 12.0.112.0.1npm install uuid@12.0.1
📦npmuuid13.0.0&&< 13.0.113.0.1npm install uuid@13.0.1

Detection & mitigation playbook

Open-source dependency
  1. Detect

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

  2. Fix

    Update uuid to 11.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w5hq-g745-h8pq 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-w5hq-g745-h8pq can be triaged on real exposure rather than presence alone.

Tailored to GHSA-w5hq-g745-h8pq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

This is a Moderate impact flaw. The `uuid` library, as used in Red Hat products, is susceptible to out-of-bounds writes when applications provide undersized external buffers for UUID generation. This can lead to data corruption or unintended information disclosure within the context of the vulnerable application, but…

ProductFixed inAdvisory
Red Hat Openshift Data Foundation 4.18odf4/cephcsi-rhel9:1786705347RHSA-2026:56431
Red Hat Openshift Data Foundation 4.22odf4/cephcsi-rhel9:1787057250RHSA-2026:56928

Frequently Asked Questions

### Summary The `v3()`, `v5()`, and `v6()` [API methods](https://github.com/uuidjs/uuid#api-summary) (not `uuid` release versions) accept external output buffers but do not reject out-of-range writes (small `buf` or large `offset`). By contrast, `v4()`, `v1()`, and `v7()` API methods explicitly throw `RangeError` on invalid bounds. This inconsistency allows **silent partial writes** into caller-provided buffers. ### Affected code - `src/v35.ts` (`v3()`/`v5()` path) writes `buf[offset + i]` without bounds validation. - `src/v6.ts` writes `buf[offset + i]` without bounds validation. ###
O3 Security · Impact-Aware SCA

Is GHSA-w5hq-g745-h8pq in your dependencies?

O3 Security finds GHSA-w5hq-g745-h8pq across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-w5hq-g745-h8pq: uuid (High 7.5) | O3 Security