Description
A vulnerability in the MIT Kerberos implementation allows GSSAPI-protected messages using RC4-HMAC-MD5 to be spoofed due to weaknesses in the MD5 checksum design. If RC4 is preferred over stronger encryption types, an attacker could exploit MD5 collisions to forge message integrity codes. This may lead to unauthorized message tampering.
References10
- access.redhat.com/errata/RHSA-2025:11487
- access.redhat.com/errata/RHSA-2025:13664
- access.redhat.com/errata/RHSA-2025:13777
- access.redhat.com/errata/RHSA-2025:15000
- access.redhat.com/errata/RHSA-2025:15001
- access.redhat.com/errata/RHSA-2025:15002
- access.redhat.com/errata/RHSA-2025:15003
- access.redhat.com/errata/RHSA-2025:15004
- access.redhat.com/errata/RHSA-2025:8411
- access.redhat.com/errata/RHSA-2025:9418
Metrics
- CVSS 3.1
-
5.9
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N - EPSS — exploit probability
- 0% percentile: 29 · as of 7 November 2026
- CWE
- CWE-328
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.