CVE-2026-88038

medium

Assigned by CNA: openjs

Published 2026-09-10 · Modified 2026-09-10

Discuss on Community Propose mitigation

CVSS v3

4.8

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS v4 NEW

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not yet in upstream

VIR risk

4.8

Description

cookies is a Node.js library for reading and writing HTTP cookies, used by Koa via ctx.cookies. In versions before 0.9.2 the library validates the cookie name and value against character sets that reject the semicolon separator, but the domain and path options are checked only against a permissive RFC 7230 field-content matcher that allows semicolons, and both are written into the Set-Cookie header unescaped. An application that passes untrusted or request-derived data into the domain or path option can therefore inject additional cookie attributes, overriding SameSite, Secure, HttpOnly, or Domain on the cookies the application issues. This is a Set-Cookie attribute injection issue (CWE-74). The issue is fixed in cookies 0.9.2, which validates domain and path against RFC 6265 character sets. As a workaround, keep domain and path application-set rather than derived from untrusted input.

Predictions

Exploit likelihood

58%

Patch ETA

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Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

CWEs

CWE-74

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.