Red Hat Security Advisory: Red Hat build of Keycloak 26.2.5 Security Update
Affects Red HatSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 7.5 High : upgrade Red Hat xstream to 1.4.21 soon.
Data as of 3 Nov 2026, 10:57 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 7.5 |
|---|
- EPSS
- 2.0% chance of exploitation in 30 days – higher than 80% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.4.21
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 7 Nov 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Upgrade com.thoughtworks.xstream/xstream to 1.4.21.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Mavencom.thoughtworks.xstream/xstreampkg:maven/com.thoughtworks.xstream/xstreamOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released updated packages for the Red Hat build of Keycloak 26.2.5 that address these vulnerabilities. Users should back up their existing installations, including applications, configuration files, and databases, before applying the update. Applying the official update from Red Hat is the recommended mitigation. No other specific mitigations or workarounds are indicated in the advisory.
Description
Red Hat has issued a security update for its build of Keycloak 26.2.5 addressing two vulnerabilities: a denial of service vulnerability in XStream caused by a stack overflow from a manipulated binary input stream (CVE-2024-47072), and a hostname verification issue in Keycloak (CVE-2025-3501). These vulnerabilities affect the authentication and single sign-on capabilities provided by Keycloak. The update is classified as important and users are advised to back up their installations before applying the update.