CVE-2024-26689: Linux kernel · ceph: prevent use-after-free in encode_cap_msg()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High · fixed in 3.13.0-210.261 : patch Linux kernel soon.
Data as of 12 Nov 2026, 18:50 UTC
- Patch
- Available – fixed in 3.13.0-210.261, 4.4.0-1143.149, 4.15.0-1188.203~14.04.1 +83
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 3 Apr 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-6766-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6795-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6828-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6900-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7495-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7495-2 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu Pro Realtime 24.04 LTSlinux-raspi-realtimepkg:deb/ubuntu/linux-raspi-realtime?arch=source&distro=realtime/nobleOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-allwinner-5.19pkg:deb/ubuntu/linux-allwinner-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-aws-5.19pkg:deb/ubuntu/linux-aws-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-aws-6.2pkg:deb/ubuntu/linux-aws-6.2?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: ceph: prevent use-after-free in encode_cap_msg() In fs/ceph/caps.c, in encode_cap_msg(), "use after free" error was caught by KASAN at this line - 'ceph_buffer_get(arg->xattr_buf);'. This implies before the refcount could be increment here, it was freed. In same file, in "handle_cap_grant()" refcount is decremented by this line - 'ceph_buffer_put(ci->i_xattrs.blob);'. It appears that a race occurred and resource was freed by the latter line before the former line could increment it. encode_cap_msg() is called by __send_cap() and __send_cap() is called by ceph_check_caps() after calling __prep_cap(). __prep_cap() is where arg->xattr_buf is assigned to ci->i_xattrs.blob. This is the spot where the refcount must be increased to prevent "use after free" error.
References
- ubuntu.com/security/CVE-2024-26689 (opens in a new tab)
- git.kernel.org/linus/cda4672da1c26835dcbd7aec2bfed954eda9b5ef (opens in a new tab)
- git.kernel.org/stable/c/8180d0c27b93a6eb60da1b08ea079e3926328214 (opens in a new tab)
- git.kernel.org/stable/c/70e329b440762390258a6fe8c0de93c9fdd56c77 (opens in a new tab)
- git.kernel.org/stable/c/f3f98d7d84b31828004545e29fd7262b9f444139 (opens in a new tab)
- git.kernel.org/stable/c/ae20db45e482303a20e56f2db667a9d9c54ac7e7 (opens in a new tab)
- git.kernel.org/stable/c/7958c1bf5b03c6f1f58e724dbdec93f8f60b96fc (opens in a new tab)
- git.kernel.org/stable/c/cda4672da1c26835dcbd7aec2bfed954eda9b5ef (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-26689 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6795-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6828-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6900-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7495-1 (opens in a new tab)