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OpenAdvisories
Medium · 5.3 CVE-2026-58216 EUVD-2026-51177GHSA-vc9h-gm8g-6j4x

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

Published Jul 30, 2026 · Updated Jul 31, 2026 · Assigned by redhat

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.

Affected products

VendorProductAffectedFixed
Red Hat Red Hat Enterprise Linux 10 — —
Red Hat Red Hat Enterprise Linux 6 — —
Red Hat Red Hat Enterprise Linux 7 — —
Red Hat Red Hat Enterprise Linux 8 — —
Red Hat Red Hat Enterprise Linux 9 — —
Red Hat Red Hat OpenShift Container Platform 4 — —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 samba 2:4.24.5+dfsg-1 —
Debian 13 samba 2:4.22.10+dfsg-0+deb13u2 —
Debian 12 samba No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.04 LTS samba 2:4.23.6+dfsg-1ubuntu2.2 —
Ubuntu 24.04 LTS samba 2:4.19.5+dfsg-4ubuntu9.7 —
Ubuntu 22.04 LTS samba 2:4.15.13+dfsg-0ubuntu1.13 —
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 20.04 LTS samba No fix yet —
Ubuntu Pro 18.04 LTS samba No fix yet —
Ubuntu Pro 16.04 LTS samba No fix yet —
Ubuntu Pro 14.04 LTS samba No fix yet —
ReleasePackageFixed inAdvisory
SLES 15 SP7 samba 4.21.10+git.533.31d7e5508d-150700.3.29.1 SUSE-SU-2026:3363-1
SLES 15 SP6 samba 4.19.8+git.501.67274891bc-150600.3.29.1 SUSE-SU-2026:3364-1
SLES 15 SP5 samba 4.17.12+git.581.f49579c6cd-150500.3.42.1 SUSE-SU-2026:3365-1
SLES 15 SP4 samba 4.15.13+git.808.eeca19f5e1-150400.3.52.1 SUSE-SU-2026:3362-1
SLES 12 SP5 samba 4.15.13+git.729.a8ce057e8d-3.109.1 SUSE-SU-2026:3367-1
Show 12 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 samba 4.22.11+git.552.66cfeb7de0a-160000.1.1 SUSE-SU-2026:23152-1, SUSE-SU-2026:23129-1
SLES for SAP 15 SP6 samba 4.19.8+git.501.67274891bc-150600.3.29.1 SUSE-SU-2026:3364-1
SLES for SAP 15 SP5 samba 4.17.12+git.581.f49579c6cd-150500.3.42.1 SUSE-SU-2026:3365-1
SLES for SAP 15 SP4 samba 4.15.13+git.808.eeca19f5e1-150400.3.52.1 SUSE-SU-2026:3362-1
SLES 16.0 samba 4.22.11+git.552.66cfeb7de0a-160000.1.1 SUSE-SU-2026:23152-1, SUSE-SU-2026:23129-1
SLE Micro 6.2 samba 4.22.9+git.538.af6cb4fb2e-160000.1.1 SUSE-SU-2026:23003-1, SUSE-SU-2026:22977-1
SLE Micro 5.5 samba 4.17.12+git.581.f49579c6cd-150500.3.42.1 SUSE-SU-2026:3365-1
SLE Micro 5.4 samba 4.15.13+git.808.eeca19f5e1-150400.3.52.1 SUSE-SU-2026:3362-1
SLE Micro 5.3 samba 4.15.13+git.808.eeca19f5e1-150400.3.52.1 SUSE-SU-2026:3362-1
SLE HPC 15 SP5 samba 4.17.12+git.581.f49579c6cd-150500.3.42.1 SUSE-SU-2026:3365-1
SLE HPC 15 SP4 samba 4.15.13+git.808.eeca19f5e1-150400.3.52.1 SUSE-SU-2026:3362-1
SUSE Enterprise Storage 7.1 samba 4.15.13+git.808.eeca19f5e1-150300.3.106.1 SUSE-SU-2026:3366-1
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed samba 4.24.5+git.481.dba78dbdea-1.1 openSUSE-SU-2026:11431-1
openSUSE Leap 16.0 samba 4.22.9+git.538.af6cb4fb2e-160000.1.1 openSUSE-SU-2026:21540-1, openSUSE-SU-2026:21475-1

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 samba No fix yet —

Advisories 14

References