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Version: v1.1.x

CVE-2026-9679

CVE Details

Visit the official vulnerability details page for CVE-2026-9679 to learn more.

Initial Publication

06/17/2026

Last Update

06/25/2026

Third Party Dependency

undici

NIST CVE Summary

Impact: undici's cookie parser in parseSetCookie percent-decodes cookie values via qsUnescape, turning encoded sequences like %0D%0A, %00, %3B, and %3D into their literal byte equivalents. RFC 6265 §5.4 does not specify any decoding and browsers do not decode either.

Applications that parse a Set-Cookie header and then forward the parsed value into a response header (proxies, middleware, SSR frameworks) become vulnerable to HTTP response header injection: an attacker-controlled upstream can inject arbitrary Set-Cookie, Location, or Cache-Control headers into the application's downstream response, enabling session fixation, open redirect, or cache poisoning.

Affected applications are those that use undici's cookie parsing (parseSetCookie, parseCookie, getSetCookies) and forward the parsed cookie value into a response header.

This was introduced in undici 7.0.0 via PR #3789.

Patches: Upgrade to undici v6.26.0, v7.28.0 or v8.5.0.

Workarounds: If upgrade is not immediately possible, do not forward values returned by parseSetCookie/parseCookie/getSetCookies directly into response headers; sanitize the value first to strip or reject CR, LF, NUL, ;, and = bytes.

CVE Severity

5.9

Our Official Summary

Investigation is ongoing to determine how this vulnerability affects our products.

Status

Analyzed

Affected Products & Versions

VersionPaletteAIPaletteAI VerteX
1.1.6⚠️ Impacted⚠️ Impacted

Revision History

No revisions available.