---
id: CVE-2026-115779
title: >-
  Effect: Cookie attribute injection via domain, path, and name fields in
  @effect/platform makeCookie()
summary: >-
  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 pat…
severity: medium
cvss: 6.3
cvssVector: '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'
cvssSource: cna
cwe:
  - CWE-74
vendor: Effect-TS
product: effect
affected:
  - 'effect >= 4.0.0-beta.0, < 4.0.0-beta.103'
  - 'platform >= 0.1.0, < 0.97.1'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-03T21:26:42.883505Z'
published: '2026-11-03'
updated: '2026-11-03'
sourceUpdated: '2026-11-03T21:26:55.431Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-115779'
references:
  - url: >-
      https://github.com/Effect-TS/effect/security/advisories/GHSA-chp3-j5qr-2vfr
    label: >-
      https://github.com/Effect-TS/effect/security/advisories/GHSA-chp3-j5qr-2vfr
  - url: 'https://github.com/Effect-TS/effect/pull/6763'
    label: 'https://github.com/Effect-TS/effect/pull/6763'
  - url: 'https://github.com/Effect-TS/effect/pull/6765'
    label: 'https://github.com/Effect-TS/effect/pull/6765'
  - url: >-
      https://github.com/Effect-TS/effect/commit/4a57af24011db1d66e947289d2f7ffc2074696d2
    label: >-
      https://github.com/Effect-TS/effect/commit/4a57af24011db1d66e947289d2f7ffc2074696d2
  - url: >-
      https://github.com/Effect-TS/effect/commit/5859b373b9be04d5037a594196b4743ad80379bd
    label: >-
      https://github.com/Effect-TS/effect/commit/5859b373b9be04d5037a594196b4743ad80379bd
  - url: 'https://github.com/Effect-TS/effect/releases/tag/@effect/platform@0.97.1'
    label: 'https://github.com/Effect-TS/effect/releases/tag/@effect/platform@0.97.1'
  - url: 'https://github.com/Effect-TS/effect/releases/tag/effect@4.0.0-beta.103'
    label: 'https://github.com/Effect-TS/effect/releases/tag/effect@4.0.0-beta.103'
tags:
  - cve.org
epss: 0.00627
epssPercentile: 0.50315
ingestedAt: '2026-11-05T20:33:06.524Z'
---

## Overview

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.

## Affected

- `effect >= 4.0.0-beta.0, < 4.0.0-beta.103`
- `platform >= 0.1.0, < 0.97.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.