Http4s: CookieJar middleware accepts arbitrary Set-Cookie domain

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.8 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N

EPSS

• CVE-2026-69214: 0.40% estimated exploitation activity in the next 30 days; percentile 33.72 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

When processing a Set-Cookie from a response, the CookieJar client middleware trusts the server-supplied Domain attribute verbatim, with no check that it domain-matches the host that sent the cookie (RFC6265 §5.3 step 6) and no public suffix check. A malicious or compromised server can therefore plant a cookie for any domain in the cookie jar, which is subsequently set on the client's next request to that victim domain, enabling session fixation or overwriting security-relevant cookies. Impact Session fixation and overwrite of security-relevant cookies for arbitrary domains contacted by the same wrapped client. Preconditions - Application uses the CookieJar client middleware. - Application contacts an attacker-controlled (or compromised) server using the same jar it uses for trusted hosts. Workarounds - Do not share a CookieJar across trusted and untrusted targets. Note This middleware still does not implement public suffix rejection.

Published by the source

15 Sep 2026, 20:00 UTC

Last modified by the source

15 Sep 2026, 20:15 UTC

Source last checked

26 Oct 2026, 16:55 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-wv64-j4fq-5f9x

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-wv64-j4fq-5f9x

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# Patch Next advisory brief: CVE-2026-69214

Advisory: Http4s: CookieJar middleware accepts arbitrary Set-Cookie domain
IDs: CVE-2026-69214, GHSA-wv64-j4fq-5f9x
Record: https://patchnext.com/advisories/cve-2026-69214 (revision 2, source checked 26 Oct 2026, 16:55 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.http4s:http4s-client_2.12 0.23.35; org.http4s:http4s-client_3 1.0.0-M47, 0.23.35; org.http4s:http4s-client_2.13 1.0.0-M47, 0.23.35. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.http4s:http4s-client_2.12: affected <= 0.23.34; fixed in 0.23.35
- Maven org.http4s:http4s-client_3: affected >= 1.0.0-M1, <= 1.0.0-M46; <= 0.23.34; fixed in 0.23.35, 1.0.0-M47
- Maven org.http4s:http4s-client_2.13: affected <= 0.23.34; >= 1.0.0-M1, <= 1.0.0-M46; fixed in 0.23.35, 1.0.0-M47

## Suggested inspection (read-only)
- Maven org.http4s:http4s-client_2.12: check the installed version with your package manager.
- Maven org.http4s:http4s-client_3: check the installed version with your package manager.
- Maven org.http4s:http4s-client_2.13: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.http4s:http4s-client_2.12, org.http4s:http4s-client_3, org.http4s:http4s-client_2.13.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-wv64-j4fq-5f9x (OSV record GHSA-wv64-j4fq-5f9x lists affected ranges: Maven org.http4s:http4s-client_2.12 >=0 =0 =1.0.0-M1 =1.0.0-M1 =0 <0.23.35 (fixed))
- Verified: https://github.com/advisories/GHSA-wv64-j4fq-5f9x (GitHub-reviewed advisory GHSA-wv64-j4fq-5f9x lists affected ranges: Maven org.http4s:http4s-client_2.12 >=0 =0 =1.0.0-M1 =1.0.0-M1 =0 <=0.23.34)

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