CVE-2026-109411
Samba: access control bypass via vfs_ceph_rgw case-insensitive open
An access control bypass flaw was identified in Samba's vfs_ceph_rgw module in it's openat() function. An authenticated user can bypass access controls to read or overwrite restricted files on shares configured with the experimental vfs_ceph_rgw module. When a client requests an existing file using mismatched character casing, the module fails to perform a case-insensitive lookup correctly, causing the server to treat the operation as creating a new file. As a result, the server skips standard permission checks on the existing file, allowing the attacker to access or overwrite sensitive data owned by other users.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
8.1
Samba: access control bypass via vfs_ceph_rgw case-insensitive open
An access control bypass flaw was identified in Samba's vfs_ceph_rgw module in it's openat() function. An authenticated user can bypass access controls to read or overwrite restricted files on shares configured with the experimental vfs_ceph_rgw module. When a client requests an existing file using mismatched character casing, the module fails to perform a case-insensitive lookup correctly, causing the server to treat the operation as creating a new file. As a result, the server skips standard permission checks on the existing file, allowing the attacker to access or overwrite sensitive data owned by other users.
- Record
CVE-2026-109411- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-178
- Updated
- 2026-11-04
EUVDEUVD-2026-112398
8.1
An access control bypass flaw was identified in Samba's vfs_ceph_rgw module in it's openat() function. An authenticated user can bypass access controls to read or overwrite restricted files on shares configured with the experimental vfs_ceph_rgw module. When a client requests an existing file using mismatched character casing, the module fails to perform a case-insensitive lookup correctly, causing the server to treat the operation as creating a new file. As a result, the server skips standard permission checks on the existing file, allowing the attacker to access or overwrite sensitive data owned by other users.
- Record
EUVD-2026-112398- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-04
GitHub AdvisoriesGHSA-pwp9-3h93-h2x8
8.1
An access control bypass flaw was found in Samba's vfs_ceph_rgw module in it's openat() function....
An access control bypass flaw was found in Samba's vfs_ceph_rgw module in it's openat() function. An authenticated user can bypass access controls to read or overwrite restricted files on shares configured with the experimental vfs_ceph_rgw module. When a client requests an existing file using mismatched character casing, the module fails to perform a case-insensitive lookup correctly, causing the server to treat the operation as creating a new file. As a result, the server skips standard permission checks on the existing file, allowing the attacker to access or overwrite sensitive data owned by other users.
- Record
GHSA-pwp9-3h93-h2x8- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-178
- Updated
- 2026-11-02
NVD
8.1
An access control bypass flaw was identified in Samba's vfs_ceph_rgw module in it's openat() function. An authenticated user can bypass access controls to read or overwrite restricted files on shares configured with the experimental vfs_ceph_rgw module. When a client requests an existing file using mismatched character casing, the module fails to perform a case-insensitive lookup correctly, causing the server to treat the operation as creating a new file. As a result, the server skips standard permission checks on the existing file, allowing the attacker to access or overwrite sensitive data owned by other users.
- Record
CVE-2026-109411- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-178
- Updated
- 2026-11-04
OSV
8.1
Samba: access control bypass via vfs_ceph_rgw case-insensitive open
An access control bypass flaw was identified in Samba's vfs_ceph_rgw module in it's openat() function. An authenticated user can bypass access controls to read or overwrite restricted files on shares configured with the experimental vfs_ceph_rgw module. When a client requests an existing file using mismatched character casing, the module fails to perform a case-insensitive lookup correctly, causing the server to treat the operation as creating a new file. As a result, the server skips standard permission checks on the existing file, allowing the attacker to access or overwrite sensitive data owned by other users.
- Record
CVE-2026-109411- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-178
- Updated
- 2026-11-05
OSVDEBIAN-CVE-2026-109411
8.1
An access control bypass flaw was identified in Samba's vfs_ceph_rgw module in it's openat() function. An authenticated user can bypass access controls to read or overwrite restricted files on shares configured with the experimental vfs_ceph_rgw module. When a client requests an existing file using mismatched character casing, the module fails to perform a case-insensitive lookup correctly, causing the server to treat the operation as creating a new file. As a result, the server skips standard permission checks on the existing file, allowing the attacker to access or overwrite sensitive data owned by other users.
- Record
DEBIAN-CVE-2026-109411- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-05
OSVUBUNTU-CVE-2026-109411
8.1
An access control bypass flaw was identified in Samba's vfs_ceph_rgw module in it's openat() function. An authenticated user can bypass access controls to read or overwrite restricted files on shares configured with the experimental vfs_ceph_rgw module. When a client requests an existing file using mismatched character casing, the module fails to perform a case-insensitive lookup correctly, causing the server to treat the operation as creating a new file. As a result, the server skips standard permission checks on the existing file, allowing the attacker to access or overwrite sensitive data owned by other users.
- Record
UBUNTU-CVE-2026-109411- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-05
OSVopenSUSE-SU-2026:12334-1 No score
ctdb-4.25.1+git.476.bfc358351cb-1.1 on GA media
These are all security issues fixed in the ctdb-4.25.1+git.476.bfc358351cb-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2026:12334-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
sambaDebian:14 |
before 2:4.25.1+dfsg-1, plus listed versions 2:4.22.3+dfsg-42:4.22.4+dfsg-12:4.22.4+dfsg-1~deb13u12:4.22.4+dfsg-1~deb13u1~bpo12+12:4.23.0+dfsg-1 Show 35 moreShow less2:4.23.0+dfsg-22:4.23.0+dfsg-32:4.23.0~rc1+dfsg-12:4.23.0~rc2+dfsg-12:4.23.0~rc3+dfsg-12:4.23.1+dfsg-12:4.23.2+dfsg-12:4.23.3+dfsg-12:4.23.3+dfsg-1~bpo13+12:4.23.4+dfsg-12:4.23.4+dfsg-1~bpo13+12:4.23.5+dfsg-12:4.23.5+dfsg-1~bpo13+12:4.23.6+dfsg-12:4.23.6+dfsg-22:4.23.6+dfsg-2~bpo13+12:4.24.0+dfsg-12:4.24.0~rc1+dfsg-12:4.24.0~rc1+dfsg-22:4.24.0~rc1+dfsg-32:4.24.0~rc2+dfsg-12:4.24.1+dfsg-12:4.24.2+dfsg-12:4.24.2+dfsg-1~bpo13+12:4.24.3+dfsg-12:4.24.3+dfsg-1~bpo13+12:4.24.4+dfsg-12:4.24.4+dfsg-1~bpo13+12:4.24.5+dfsg-12:4.24.5+dfsg-1~bpo13+12:4.24.6+dfsg-12:4.24.7+dfsg-12:4.24.7+dfsg-1~bpo13+12:4.25.0+dfsg-12:4.25.0~rc1+dfsg-1 |
2:4.25.1+dfsg-1 |
sambaUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 2:3.6.18-1ubuntu32:4.0.10+dfsg-4ubuntu22:4.0.13+dfsg-1ubuntu12:4.1.3+dfsg-2ubuntu22:4.1.3+dfsg-2ubuntu3 Show 45 moreShow less2:4.1.3+dfsg-2ubuntu42:4.1.3+dfsg-2ubuntu52:4.1.6+dfsg-1ubuntu12:4.1.6+dfsg-1ubuntu22:4.1.6+dfsg-1ubuntu2.14.04.12:4.1.6+dfsg-1ubuntu2.14.04.22:4.1.6+dfsg-1ubuntu2.14.04.32:4.1.6+dfsg-1ubuntu2.14.04.42:4.1.6+dfsg-1ubuntu2.14.04.52:4.1.6+dfsg-1ubuntu2.14.04.72:4.1.6+dfsg-1ubuntu2.14.04.82:4.1.6+dfsg-1ubuntu2.14.04.92:4.1.6+dfsg-1ubuntu2.14.04.112:4.1.6+dfsg-1ubuntu2.14.04.122:4.1.6+dfsg-1ubuntu2.14.04.132:4.3.8+dfsg-0ubuntu0.14.04.22:4.3.9+dfsg-0ubuntu0.14.04.12:4.3.9+dfsg-0ubuntu0.14.04.32:4.3.11+dfsg-0ubuntu0.14.04.12:4.3.11+dfsg-0ubuntu0.14.04.22:4.3.11+dfsg-0ubuntu0.14.04.32:4.3.11+dfsg-0ubuntu0.14.04.42:4.3.11+dfsg-0ubuntu0.14.04.62:4.3.11+dfsg-0ubuntu0.14.04.72:4.3.11+dfsg-0ubuntu0.14.04.82:4.3.11+dfsg-0ubuntu0.14.04.92:4.3.11+dfsg-0ubuntu0.14.04.102:4.3.11+dfsg-0ubuntu0.14.04.112:4.3.11+dfsg-0ubuntu0.14.04.122:4.3.11+dfsg-0ubuntu0.14.04.132:4.3.11+dfsg-0ubuntu0.14.04.142:4.3.11+dfsg-0ubuntu0.14.04.162:4.3.11+dfsg-0ubuntu0.14.04.172:4.3.11+dfsg-0ubuntu0.14.04.192:4.3.11+dfsg-0ubuntu0.14.04.202:4.3.11+dfsg-0ubuntu0.14.04.20+esm12:4.3.11+dfsg-0ubuntu0.14.04.20+esm22:4.3.11+dfsg-0ubuntu0.14.04.20+esm32:4.3.11+dfsg-0ubuntu0.14.04.20+esm42:4.3.11+dfsg-0ubuntu0.14.04.20+esm62:4.3.11+dfsg-0ubuntu0.14.04.20+esm72:4.3.11+dfsg-0ubuntu0.14.04.20+esm82:4.3.11+dfsg-0ubuntu0.14.04.20+esm92:4.3.11+dfsg-0ubuntu0.14.04.20+esm112:4.3.11+dfsg-0ubuntu0.14.04.20+esm12 |
None known |
sambaUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 2:4.1.17+dfsg-4ubuntu22:4.1.20+dfsg-1ubuntu12:4.1.20+dfsg-1ubuntu22:4.1.20+dfsg-1ubuntu32:4.1.20+dfsg-1ubuntu5 Show 41 moreShow less2:4.3.3+dfsg-1ubuntu12:4.3.3+dfsg-1ubuntu22:4.3.3+dfsg-1ubuntu32:4.3.6+dfsg-1ubuntu12:4.3.8+dfsg-0ubuntu12:4.3.9+dfsg-0ubuntu0.16.04.12:4.3.9+dfsg-0ubuntu0.16.04.22:4.3.9+dfsg-0ubuntu0.16.04.32:4.3.11+dfsg-0ubuntu0.16.04.12:4.3.11+dfsg-0ubuntu0.16.04.32:4.3.11+dfsg-0ubuntu0.16.04.52:4.3.11+dfsg-0ubuntu0.16.04.62:4.3.11+dfsg-0ubuntu0.16.04.72:4.3.11+dfsg-0ubuntu0.16.04.82:4.3.11+dfsg-0ubuntu0.16.04.92:4.3.11+dfsg-0ubuntu0.16.04.102:4.3.11+dfsg-0ubuntu0.16.04.112:4.3.11+dfsg-0ubuntu0.16.04.122:4.3.11+dfsg-0ubuntu0.16.04.132:4.3.11+dfsg-0ubuntu0.16.04.152:4.3.11+dfsg-0ubuntu0.16.04.162:4.3.11+dfsg-0ubuntu0.16.04.172:4.3.11+dfsg-0ubuntu0.16.04.182:4.3.11+dfsg-0ubuntu0.16.04.192:4.3.11+dfsg-0ubuntu0.16.04.202:4.3.11+dfsg-0ubuntu0.16.04.212:4.3.11+dfsg-0ubuntu0.16.04.232:4.3.11+dfsg-0ubuntu0.16.04.242:4.3.11+dfsg-0ubuntu0.16.04.252:4.3.11+dfsg-0ubuntu0.16.04.262:4.3.11+dfsg-0ubuntu0.16.04.272:4.3.11+dfsg-0ubuntu0.16.04.282:4.3.11+dfsg-0ubuntu0.16.04.292:4.3.11+dfsg-0ubuntu0.16.04.302:4.3.11+dfsg-0ubuntu0.16.04.312:4.3.11+dfsg-0ubuntu0.16.04.322:4.3.11+dfsg-0ubuntu0.16.04.342:4.3.11+dfsg-0ubuntu0.16.04.34+esm12:4.3.11+dfsg-0ubuntu0.16.04.34+esm22:4.3.11+dfsg-0ubuntu0.16.04.34+esm32:4.3.11+dfsg-0ubuntu0.16.04.34+esm4 |
None known |
sambaUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 2:4.6.7+dfsg-1ubuntu32:4.7.1+dfsg-1ubuntu12:4.7.3+dfsg-1ubuntu12:4.7.4+dfsg-1ubuntu12:4.7.6+dfsg~ubuntu-0ubuntu1 Show 27 moreShow less2:4.7.6+dfsg~ubuntu-0ubuntu22:4.7.6+dfsg~ubuntu-0ubuntu2.22:4.7.6+dfsg~ubuntu-0ubuntu2.42:4.7.6+dfsg~ubuntu-0ubuntu2.52:4.7.6+dfsg~ubuntu-0ubuntu2.62:4.7.6+dfsg~ubuntu-0ubuntu2.72:4.7.6+dfsg~ubuntu-0ubuntu2.92:4.7.6+dfsg~ubuntu-0ubuntu2.102:4.7.6+dfsg~ubuntu-0ubuntu2.112:4.7.6+dfsg~ubuntu-0ubuntu2.132:4.7.6+dfsg~ubuntu-0ubuntu2.142:4.7.6+dfsg~ubuntu-0ubuntu2.152:4.7.6+dfsg~ubuntu-0ubuntu2.162:4.7.6+dfsg~ubuntu-0ubuntu2.172:4.7.6+dfsg~ubuntu-0ubuntu2.182:4.7.6+dfsg~ubuntu-0ubuntu2.192:4.7.6+dfsg~ubuntu-0ubuntu2.202:4.7.6+dfsg~ubuntu-0ubuntu2.212:4.7.6+dfsg~ubuntu-0ubuntu2.232:4.7.6+dfsg~ubuntu-0ubuntu2.242:4.7.6+dfsg~ubuntu-0ubuntu2.262:4.7.6+dfsg~ubuntu-0ubuntu2.272:4.7.6+dfsg~ubuntu-0ubuntu2.282:4.7.6+dfsg~ubuntu-0ubuntu2.292:4.7.6+dfsg~ubuntu-0ubuntu2.29+esm12:4.7.6+dfsg~ubuntu-0ubuntu2.29+esm22:4.7.6+dfsg~ubuntu-0ubuntu2.29+esm3 |
None known |
sambaUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 2:4.10.7+dfsg-0ubuntu22:4.10.7+dfsg-0ubuntu32:4.11.1+dfsg-3ubuntu12:4.11.1+dfsg-3ubuntu22:4.11.1+dfsg-3ubuntu4 Show 32 moreShow less2:4.11.5+dfsg-1ubuntu12:4.11.5+dfsg-1ubuntu22:4.11.6+dfsg-0ubuntu12:4.11.6+dfsg-0ubuntu1.12:4.11.6+dfsg-0ubuntu1.22:4.11.6+dfsg-0ubuntu1.32:4.11.6+dfsg-0ubuntu1.42:4.11.6+dfsg-0ubuntu1.52:4.11.6+dfsg-0ubuntu1.62:4.11.6+dfsg-0ubuntu1.82:4.11.6+dfsg-0ubuntu1.92:4.11.6+dfsg-0ubuntu1.102:4.13.14+dfsg-0ubuntu0.20.04.12:4.13.14+dfsg-0ubuntu0.20.04.22:4.13.14+dfsg-0ubuntu0.20.04.32:4.13.14+dfsg-0ubuntu0.20.04.42:4.13.17~dfsg-0ubuntu0.21.04.12:4.13.17~dfsg-0ubuntu0.21.04.22:4.13.17~dfsg-0ubuntu1.20.04.12:4.13.17~dfsg-0ubuntu1.20.04.22:4.13.17~dfsg-0ubuntu1.20.04.42:4.13.17~dfsg-0ubuntu1.20.04.52:4.15.13+dfsg-0ubuntu0.20.04.12:4.15.13+dfsg-0ubuntu0.20.04.22:4.15.13+dfsg-0ubuntu0.20.04.32:4.15.13+dfsg-0ubuntu0.20.04.42:4.15.13+dfsg-0ubuntu0.20.04.52:4.15.13+dfsg-0ubuntu0.20.04.62:4.15.13+dfsg-0ubuntu0.20.04.72:4.15.13+dfsg-0ubuntu0.20.04.82:4.15.13+dfsg-0ubuntu0.20.04.8+esm12:4.15.13+dfsg-0ubuntu0.20.04.8+esm2 |
None known |
sambaUbuntu:22.04:LTS |
All versions, plus listed versions 2:4.13.5+dfsg-2ubuntu22:4.13.5+dfsg-2ubuntu32:4.13.14+dfsg-0ubuntu12:4.13.14+dfsg-0ubuntu22:4.15.5~dfsg-0ubuntu1 Show 19 moreShow less2:4.15.5~dfsg-0ubuntu22:4.15.5~dfsg-0ubuntu42:4.15.5~dfsg-0ubuntu52:4.15.5~dfsg-0ubuntu5.12:4.15.9+dfsg-0ubuntu0.22:4.15.9+dfsg-0ubuntu0.32:4.15.13+dfsg-0ubuntu12:4.15.13+dfsg-0ubuntu1.12:4.15.13+dfsg-0ubuntu1.22:4.15.13+dfsg-0ubuntu1.32:4.15.13+dfsg-0ubuntu1.42:4.15.13+dfsg-0ubuntu1.52:4.15.13+dfsg-0ubuntu1.62:4.15.13+dfsg-0ubuntu1.72:4.15.13+dfsg-0ubuntu1.82:4.15.13+dfsg-0ubuntu1.92:4.15.13+dfsg-0ubuntu1.102:4.15.13+dfsg-0ubuntu1.122:4.15.13+dfsg-0ubuntu1.13 |
None known |
sambaUbuntu:24.04:LTS |
All versions, plus listed versions 2:4.18.6+dfsg-1ubuntu22:4.18.6+dfsg-1ubuntu2.12:4.18.6+dfsg-1ubuntu2.22:4.19.4+dfsg-3ubuntu12:4.19.5+dfsg-1ubuntu1 Show 9 moreShow less2:4.19.5+dfsg-4ubuntu72:4.19.5+dfsg-4ubuntu82:4.19.5+dfsg-4ubuntu92:4.19.5+dfsg-4ubuntu9.22:4.19.5+dfsg-4ubuntu9.32:4.19.5+dfsg-4ubuntu9.42:4.19.5+dfsg-4ubuntu9.62:4.19.5+dfsg-4ubuntu9.72:4.19.5+dfsg-4ubuntu9.8 |
None known |
sambaUbuntu:26.10 |
All versions, plus listed versions 2:4.23.6+dfsg-1ubuntu22:4.23.6+dfsg-1ubuntu32:4.24.4+dfsg-1ubuntu12:4.24.6+dfsg-1ubuntu12:4.24.7+dfsg-1ubuntu1 |
None known |
sambaUbuntu:26.04:LTS |
All versions, plus listed versions 2:4.22.3+dfsg-4ubuntu22:4.22.3+dfsg-4ubuntu2.12:4.22.3+dfsg-4ubuntu32:4.22.3+dfsg-4ubuntu42:4.23.4+dfsg-1ubuntu1 Show 5 moreShow less2:4.23.5+dfsg-1ubuntu22:4.23.6+dfsg-1ubuntu12:4.23.6+dfsg-1ubuntu22:4.23.6+dfsg-1ubuntu2.12:4.23.6+dfsg-1ubuntu2.2 |
None known |
sambaopenSUSE:Tumbleweed |
before 4.25.1+git.476.bfc358351cb-1.1 | 4.25.1+git.476.bfc358351cb-1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | CVE List | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-109411 is a high vulnerability (CVSS 8.1) in Samba, published October 28, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.65%, the 51st percentile. Fixed in samba 2:4.25.1+dfsg-1.
References
access.redhat.com/security/cve/CVE-2026-109411
attachments.samba.org/attachment.cgi?id=19294
attachments.samba.org/attachment.cgi?id=19295
bugzilla.redhat.com/show_bug.cgi?id=2552136
bugzilla.samba.org/show_bug.cgi?id=16276
nvd.nist.gov/vuln/detail/CVE-2026-109411
Show 8 moreShow less
github.com/advisories/GHSA-pwp9-3h93-h2x8
access.redhat.com/downloads/content/package-browser
github.com/CVEProject/cvelistV5/tree/main/cves/2026/109xxx/CVE-2026-109411.json
gitlab.com/samba-team/samba
security-tracker.debian.org/tracker/CVE-2026-109411
ubuntu.com/security/CVE-2026-109411
cve.org/CVERecord?id=CVE-2026-109411
suse.com/security/cve/CVE-2026-109411
Left out here: 3 versions. The JSON record has them.