Description
All Samba versions 4.x.x before 4.9.17, 4.10.x before 4.10.11 and 4.11.x before 4.11.3 have an issue, where the S4U (MS-SFU) Kerberos delegation model includes a feature allowing for a subset of clients to be opted out of constrained delegation in any way, either S4U2Self or regular Kerberos authentication, by forcing all tickets for these clients to be non-forwardable. In AD this is implemented by a user attribute delegation_not_allowed (aka not-delegated), which translates to disallow-forwardable. However the Samba AD DC does not do that for S4U2Self and does set the forwardable flag even if the impersonated client has the not-delegated flag set.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | samba | all versions 4.11.x before 4.11.3, all versions 4.10.x before 4.10.11, all versions 4.x.x before 4.9.17 | — |
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.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | heimdal | 7.7.0+dfsg-1 | — |
| Debian 14 | samba | 2:4.11.3+dfsg-1 | — |
| Debian 13 | heimdal | 7.7.0+dfsg-1 | — |
| Debian 13 | samba | 2:4.11.3+dfsg-1 | — |
| Debian 12 | heimdal | 7.7.0+dfsg-1 | — |
| Debian 12 | samba | 2:4.11.3+dfsg-1 | — |
| Debian 10 | heimdal | 7.5.0+dfsg-3+deb10u1 | DLA-3206-1 |
| Debian 9 | samba | 2:4.5.16+dfsg-1+deb9u4 | DLA-2668-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | samba | 2:4.7.6+dfsg~ubuntu-0ubuntu2.14 | USN-4217-1 |
| Ubuntu 16.04 LTS | samba | 2:4.3.11+dfsg-0ubuntu0.16.04.24 | USN-4217-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | samba | 2:4.3.11+dfsg-0ubuntu0.14.04.20+esm4 | USN-4217-2 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP1 | samba | 4.9.5+git.224.86a8e66adea-3.18.1 | SUSE-SU-2019:3319-1 |
| SLES 15 | samba | 4.7.11+git.202.6edee83fb34-4.34.1 | SUSE-SU-2019:3318-1 |
| SLES 12 SP5 | ldb | 1.5.8-3.5.1 | SUSE-SU-2020:2673-1 |
| SLES 12 SP5 | samba | 4.10.17+git.203.862547088ca-3.14.1 | SUSE-SU-2020:2673-1 |
| SLES 2 | samba | 4.9.5+git.224.86a8e66adea-3.18.1 | SUSE-SU-2019:3319-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP5 | ldb | 1.5.8-3.5.1 | SUSE-SU-2020:2673-1 |
| SLES for SAP 12 SP5 | samba | 4.10.17+git.203.862547088ca-3.14.1 | SUSE-SU-2020:2673-1 |
| SUSE Package Hub 15 SP4 | libheimdal | 7.8.0-bp154.2.4.1 | openSUSE-SU-2023:0019-1 |
| SUSE Package Hub 15 SP3 | libheimdal | 7.8.0-bp153.2.4.1 | openSUSE-SU-2023:0020-1 |
| SUSE Enterprise Storage 6 | samba | 4.9.5+git.224.86a8e66adea-3.18.1 | SUSE-SU-2019:3319-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | samba | 4.14.6+git.182.2205d5224e3-1.1 | openSUSE-SU-2024:11365-1 |
| openSUSE Leap 15.4 | libheimdal | 7.8.0-bp154.2.4.1 | openSUSE-SU-2023:0019-1 |
| openSUSE Leap 15.3 | libheimdal | 7.8.0-bp153.2.4.1 | openSUSE-SU-2023:0020-1 |
| openSUSE Leap 15.1 | samba | 4.9.5+git.224.86a8e66adea-lp151.2.12.1 | openSUSE-SU-2019:2700-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | heimdal | 7.7.1-r0 | — |
| Alpine v3.24 | samba | 4.11.3-r0 | — |
| Alpine v3.23 | heimdal | 7.7.1-r0 | — |
| Alpine v3.23 | samba | 4.11.3-r0 | — |
| Alpine v3.22 | heimdal | 7.7.1-r0 | — |
| Alpine v3.22 | samba | 4.11.3-r0 | — |
| Alpine v3.21 | heimdal | 7.7.1-r0 | — |
| Alpine v3.21 | samba | 4.11.3-r0 | — |
| Alpine v3.20 | heimdal | 7.7.1-r0 | — |
| Alpine v3.20 | samba | 4.11.3-r0 | — |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | heimdal | 7.7.1-r0 | — |
| Alpine v3.19 | samba | 4.11.3-r0 | — |
| Alpine v3.18 | heimdal | 7.7.1-r0 | — |
| Alpine v3.18 | samba | 4.11.3-r0 | — |
| Alpine v3.17 | heimdal | 7.7.1-r0 | — |
| Alpine v3.17 | samba | 4.11.3-r0 | — |
| Alpine v3.16 | heimdal | 7.7.1-r0 | — |
| Alpine v3.16 | samba | 4.11.3-r0 | — |
| Alpine v3.15 | heimdal | 7.7.1-r0 | — |
| Alpine v3.15 | samba | 4.11.3-r0 | — |
| Alpine v3.14 | heimdal | 7.7.1-r0 | — |
| Alpine v3.14 | samba | 4.11.3-r0 | — |
| Alpine v3.13 | samba | 4.11.3-r0 | — |
| Alpine v3.12 | samba | 4.11.3-r0 | — |
| Alpine v3.11 | samba | 4.11.3-r0 | — |
| Alpine v3.10 | samba | 4.10.11-r0 | — |
Advisories 12
- USN-4217-1 samba vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-4217-2 samba vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-3206-1 heimdal - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2668-1 samba - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2020:2673-1 Security update for samba SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11365-1 ctdb-4.14.6+git.182.2205d5224e3-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:2700-1 Security update for samba SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:3318-1 Security update for samba SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2023:0019-1 Security update for libheimdal SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2023:0020-1 Security update for libheimdal SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:3319-1 Security update for samba SUSE / openSUSE Security Updates · May 2, 2025
- WID-SEC-2022-2051 Samba: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 27, 2022
References
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14870
- USN-4217-1 vendor-advisory
- https://security.netapp.com/advisory/ntap-20191210-0002/
- https://www.samba.org/samba/security/CVE-2019-14870.html
- USN-4217-2 vendor-advisory
- FEDORA-2019-be98a08835 vendor-advisory
- https://www.synology.com/security/advisory/Synology_SA_19_40
- openSUSE-SU-2019:2700 vendor-advisory
- FEDORA-2019-11dddb785b vendor-advisory
- GLSA-202003-52 vendor-advisory
- [debian-lts-announce] 20210529 [SECURITY] [DLA 2668-1] samba security update mailing-list
- [debian-lts-announce] 20221126 [SECURITY] [DLA 3206-1] heimdal security update mailing-list
- https://security.netapp.com/advisory/ntap-20230216-0008/
- GLSA-202310-06 vendor-advisory