Bug 2510884

Summary: CVE-2026-58216 samba: kpasswd service: kpasswd packet that contains malformed ASN.1 might cause the server to access 6 bytes of unallocated memory leading server to crash [fedora-all]
Product: [Fedora] Fedora Reporter: TEJ RATHI <trathi>
Component: sambaAssignee: Guenther Deschner <gdeschner>
Status: CLOSED ERRATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: abokovoy, anoopcs, asn, gdeschner, pfilipen, sbose, ssorce
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["762d5c73-2d76-4946-b1e1-3026a2e40161"]}
Fixed In Version: samba-4.24.5-1.fc45 samba-4.24.5-1.fc44 samba-4.23.10-1.fc43 Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2026-08-04 12:56:40 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2502721    

Description TEJ RATHI 2026-08-04 05:00:53 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

A miscalculation means an ASN.1 structure used in a Kerberos password change is assumed to be six bytes bigger than it is. This does not affect ordinary packets (the ASN.1 itself contains the correct size), but a crafted ANS1 packet could force up to six unallocated bytes to be read. The usual outcome of this will be a decryption failure and an error message, but it could make the server process crash.

Comment 1 Fedora Update System 2026-08-04 10:49:17 UTC
FEDORA-2026-3be8175017 (freeipa-4.13.2-1.fc45 and samba-4.24.5-1.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-3be8175017

Comment 2 Fedora Update System 2026-08-04 10:49:33 UTC
FEDORA-2026-fcd4630c0d (freeipa-4.13.2-1.fc44 and samba-4.24.5-1.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-fcd4630c0d

Comment 3 Fedora Update System 2026-08-04 10:49:33 UTC
FEDORA-2026-8e7fa96cf3 (freeipa-4.13.2-1.fc43 and samba-4.23.10-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-8e7fa96cf3

Comment 4 Fedora Update System 2026-08-04 12:56:40 UTC
FEDORA-2026-3be8175017 (freeipa-4.13.2-1.fc45 and samba-4.24.5-1.fc45) has been pushed to the Fedora 45 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 5 Fedora Update System 2026-08-05 01:33:39 UTC
FEDORA-2026-8e7fa96cf3 has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-8e7fa96cf3`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-8e7fa96cf3

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 6 Fedora Update System 2026-08-05 01:56:49 UTC
FEDORA-2026-fcd4630c0d has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-fcd4630c0d`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-fcd4630c0d

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 7 Fedora Update System 2026-08-06 17:17:11 UTC
FEDORA-2026-fcd4630c0d (freeipa-4.13.2-1.fc44 and samba-4.24.5-1.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 8 Fedora Update System 2026-08-07 01:37:38 UTC
FEDORA-2026-8e7fa96cf3 (freeipa-4.13.2-1.fc43 and samba-4.23.10-1.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.