CVE-2026-58216
Publication date 28 July 2026
Last updated 7 August 2026
Ubuntu priority
Description
An out-of-bounds read flaw was found in Samba's Kerberos Key Distribution Center's (KDC) password change (kpasswd) service. When processing malformed ASN.1-encoded Kerberos password change request, Samba server miscalculates the structure size and attempts to read up to six bytes beyond the end of the allocated buffer. While this out-of-bounds read typically results in a harmless decryption failure, if the read hits unmapped memory, it causes the KDC process to crash. An authenticated attacker can send a specially crafted kpasswd request containing malformed ASN.1 data to trigger the out-of-bounds read, which may cause the KDC process to terminate, resulting in a denial of service.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| samba | 26.04 LTS resolute |
Fixed 2:4.23.6+dfsg-1ubuntu2.2
|
| 24.04 LTS noble |
Fixed 2:4.19.5+dfsg-4ubuntu9.7
|
|
| 22.04 LTS jammy |
Fixed 2:4.15.13+dfsg-0ubuntu1.13
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic |
Needs evaluation
|
|
| 16.04 LTS xenial |
Needs evaluation
|
|
| 14.04 LTS trusty |
Needs evaluation
|
Severity score breakdown
CVSS version: CVSS v3.0
Base score
5.3 · Medium
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
References
Related Ubuntu Security Notices (USN)
- USN-8621-1
- Samba vulnerabilities
- 28 July 2026