CVE-2026-9496 — pacote
Fix: npm/pacote@ce804fbCVE-2026-9496 is a CWE-1333 vulnerability in pacote. A fix is available for pacote — see the affected versions and patch details below.
pacote is vulnerable to Denial of Service (DoS) via the addGitSha function
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.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-9496.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
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.
pacotenpmDescription
Versions of the package pacote from 11.2.7 and before 21.5.1 are vulnerable to Denial of Service (DoS) via the addGitSha function. An attacker can exploit this vulnerability by supplying a specially crafted spec.rawSpec value that triggers the function’s regex replacement and string-manipulation logic, causing excessive CPU consumption and potentially stalling or crashing the process.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | pacote | ≥ 11.2.7&&< 21.5.1 | 21.5.1npm install pacote@21.5.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pacote, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pacote to 21.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-9496 is resolved across your whole dependency graph.
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.
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.
A flaw was found in the pacote npm package. Pacote retrieves package metadata and archives from npm registries, Git repositories, and other sources. In affected versions, the addGitSha function strips Git committish information from a package specification using a regular expression that is vulnerable to inefficient…
To mitigate this limit the length of incoming package specifiers (spec.rawSpec) before they reach the resolution service. Enforce hard CPU time limits or timeouts on isolated build jobs and package resolution processes.Source: Red Hat security advisory for CVE-2026-9496 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 10 | nodejs22-1:22.23.2-3.el10_2 | RHSA-2026:75864 |
| Red Hat Enterprise Linux 8 | nodejs:22-8100020260928121333.6d880403 | RHSA-2026:75870 |
| Red Hat Enterprise Linux 9 | nodejs:22-9080020260928121441.rhel9 | RHSA-2026:76750 |
| Red Hat Hardened Images | grafana12-4-main-12.4.10-0.8.hum1 | RHSA-2026:72116 |
| Red Hat Hardened Images | grafana12-4-main-12.4.10-0.9.hum1 | RHSA-2026:72497 |
Frequently Asked Questions
Is CVE-2026-9496 in your dependencies?
Find it across npm, including transitive dependencies.