Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
The Maven package org.asynchttpclient:async-http-client, versions from 2.1.0 before 2.12.4 and from 3.0.0.Beta1 before 3.0.1, has a flaw where the automatic cookie store silently replaces explicitly set cookies with same-named cookies from the store. An attacker who can get a cookie into the shared store, such as through a Set-Cookie response, can cause one user's cookie to be sent in another user's requests, which may expose that user's information. Upgrade to 2.12.4 or 3.0.1. Alternatively, disable the cookie store when creating the client.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 9.2 | Critical | 4.0 | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0073, the 54th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:17 UTC First seen by agentprime
- 31 Oct 2026, 14:17 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-mfj5-cf8g-g2fv
- OSV: GHSA-mfj5-cf8g-g2fv
- github.com/AsyncHttpClient/async-http-client/security/advisories/GHSA-mfj5-cf8g-g2fv
- nvd.nist.gov/vuln/detail/CVE-2024-53990
- github.com/AsyncHttpClient/async-http-client/issues/1964
- github.com/AsyncHttpClient/async-http-client/pull/2033
- github.com/AsyncHttpClient/async-http-client/commit/d5a83362f7aed81b93ebca559746ac9be0f95425
- github.com/AsyncHttpClient/async-http-client
- github.com/AsyncHttpClient/async-http-client/blob/main/CHANGES.md#from-20-to-21