CVE-2026-115779 PUBLISHED

Effect: Cookie attribute injection via domain, path, and name fields in @effect/platform makeCookie()

Assigner: GitHub_M
Reserved: 23.10.2026 Published: 03.11.2026 Updated: 03.11.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
CVSS Score: 6.3

Product Status

Vendor Effect-TS
Product effect
Versions
  • Version >= 4.0.0-beta.0, < 4.0.0-beta.103 is affected
Vendor @effect
Product platform
Versions
  • Version >= 0.1.0, < 0.97.1 is affected

References

Problem Types

  • CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') CWE