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

printf vulnerable to Regular Expression Denial of Service (ReDoS)GHSA-xfhp-gmh8-r8v2

HIGHFix: adaltas/node-printf#32

GHSA-xfhp-gmh8-r8v2 is a high-severity (CVSS 7.5) CWE-1333 vulnerability in printf. 1 public exploit reference exists, so weaponization risk is real. A fix is available for printf — see the affected versions and patch details below.

Also known asCVE-2021-23354SNYK-JS-PRINTF-1072096
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
1 known
Exploitation data as of Oct 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
2.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs82th percentile — riskier than 82% of all scored CVEsHighest risk
0.00%0.90%1.81%2.71%0.4%2.2%Apr 26Aug 26Oct 26

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

How urgent is this, really

GHSA-xfhp-gmh8-r8v2 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.

198other npm packages depend on this — each one inherits the vulnerability until it's patched upstream
printfnpm
224Kdownloads / week

Description

The package printf before 0.6.1 are vulnerable to Regular Expression Denial of Service (ReDoS) via the regex string

/\%(?:\(([\w_.]+)\)|([1-9]\d*)\$)?([0 +\-\]*)(\*|\d+)?(\.)?(\*|\d+)?[hlL]?([\%bscdeEfFgGioOuxX])/g

in lib/printf.js. The vulnerable regular expression has cubic worst-case time complexity.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npmprintfall versions0.6.1npm install printf@0.6.1

Affected Products

1 product · 1 configurations
Application
printfadaltas
< 0.6.1
range
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

The package printf before 0.6.1 are vulnerable to Regular Expression Den…

github.comNVDMar 2021

Detection & mitigation playbook

Open-source dependency

  1. Detect

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

  2. Fix

    Update printf to 0.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xfhp-gmh8-r8v2 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

The package printf before 0.6.1 are vulnerable to Regular Expression Denial of Service (ReDoS) via the regex string ```regex /\%(?:\(([\w_.]+)\)|([1-9]\d*)\$)?([0 +\-\]*)(\*|\d+)?(\.)?(\*|\d+)?[hlL]?([\%bscdeEfFgGioOuxX])/g ``` in `lib/printf.js`. The vulnerable regular expression has cubic worst-case time complexity.
O3 Security · Impact-Aware SCA

Is GHSA-xfhp-gmh8-r8v2 in your dependencies?

Find it across npm, including transitive dependencies.

Scan my dependencies How O3 SCA works
printf vulnerable to Regular Expression Denial of Service…