Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
📦
📦 npm
Not in CISA KEV
CRITICAL severity

Prototype Pollution in mixmeGHSA-r5cq-9537-9rpf

CRITICALFix: adaltas/node-mixme@cfd5fbf

GHSA-r5cq-9537-9rpf is a critical-severity (CVSS 9.1) CWE-1321 vulnerability in mixme. A fix is available for mixme — see the affected versions and patch details below.

Also known asCVE-2021-28860CVE-2021-29491GHSA-79jw-6wg7-r9g4
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Oct 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
1.8%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs78th percentile — riskier than 78% of all scored CVEsHighest risk
0.66%1.26%1.86%2.46%1.2%1.8%Apr 26Aug 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

GHSA-r5cq-9537-9rpf by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg 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.

33other npm packages depend on this — each one inherits the vulnerability until it's patched upstream
mixmenpm
1.6Mdownloads / week

Description

In Node.js mixme, prior to v0.5.1, an attacker can add or alter properties of an object via 'proto' through the mutate() and merge() functions. The polluted attribute will be directly assigned to every object in the program. This will put the availability of the program at risk causing a potential denial of service (DoS).

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npmmixmeall versions0.5.1npm install mixme@0.5.1

Affected Products

1 product · 1 configurations
Application
mixmeadaltas
< 0.5.1
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

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

  2. Fix

    Update mixme to 0.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-r5cq-9537-9rpf is resolved across your whole dependency graph.

  3. Workarounds

    Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

Node.js mixme 0.5.0, an attacker can add or alter properties of an object via '__proto__' through the mutate() and merge() functions. The polluted attribute will be directly assigned to every object in the program. This will put the availability of the program at risk causing a potential denial of service (DoS).
O3 Security · Impact-Aware SCA

Is GHSA-r5cq-9537-9rpf in your dependencies?

Find it across npm, including transitive dependencies.

Scan my dependencies How O3 SCA works
Prototype Pollution in mixme (Critical 9.1)