Effect is a TypeScript framework that consists of several packages that work together to help build TypeScript applications.
CVE-2026-115779
Effect is a TypeScript framework that consists of several packages that work together to help build TypeScript applications. From @effect/platform 0.1.0 until 0.97.1 and effect 4.0.0-beta.0 until 4.0.0-beta.103, the name, domain, and path fields passed to makeCookie() allow semicolon delimiters that serializeCookie() writes verbatim into Set-Cookie headers. A caller that supplies attacker-controlled values can append cookie attributes, including a broader Domain or, when the caller has not set those options itself, SameSite=None or Max-Age. Encoded cookie values and CR or LF characters remain unaffected. This can widen a cookie's scope or add otherwise-unset cookie attributes. This issue is fixed in @effect/platform 0.97.1 and effect 4.0.0-beta.103.
Assessment
- CVSS
- 6.3 (v4.0)
- Severity
- Medium
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 3 November 2026
- Last updated
- 3 November 2026
- Assigner
- GitHub_M
CVSS vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
At the source
References
- https://github.com/Effect-TS/effect/security/advisories/GHSA-chp3-j5qr-2vfr
- https://github.com/Effect-TS/effect/pull/6763
- https://github.com/Effect-TS/effect/pull/6765
- https://github.com/Effect-TS/effect/commit/4a57af24011db1d66e947289d2f7ffc2074696d2
- https://github.com/Effect-TS/effect/commit/5859b373b9be04d5037a594196b4743ad80379bd
- https://github.com/Effect-TS/effect/releases/tag/@effect/platform@0.97.1
- https://github.com/Effect-TS/effect/releases/tag/effect@4.0.0-beta.103
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