CVE-2026-43304: Linux kernel · libceph: define and enforce CEPH_MAX_KEY_LEN
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in e1dc45d97975f9db65694d234fbddf1915176e16 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 12:42 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 49% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in e1dc45d97975f9db65694d234fbddf1915176e16, d82467c07b03a27c3c5469b62bb3b726305a80bb, c1a0f5f1e5e7e98c36a362ec3d1fcfd9932931ed +4
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
Description
In the Linux kernel, the following vulnerability has been resolved: libceph: define and enforce CEPH_MAX_KEY_LEN When decoding the key, verify that the key material would fit into a fixed-size buffer in process_auth_done() and generally has a sane length. The new CEPH_MAX_KEY_LEN check replaces the existing check for a key with no key material which is a) not universal since CEPH_CRYPTO_NONE has to be excluded and b) doesn't provide much value since a smaller than needed key is just as invalid as no key -- this has to be handled elsewhere anyway.
References
- git.kernel.org/stable/c/6405e8c680974bb74e2c98d5249fb52c7b12a6c6 (opens in a new tab)
- git.kernel.org/stable/c/8d745d38c88ecbed95f6b2b39857bf89f35a3244 (opens in a new tab)
- git.kernel.org/stable/c/e1dc45d97975f9db65694d234fbddf1915176e16 (opens in a new tab)
- git.kernel.org/stable/c/1b275bd49e58752efb83767a5d1aed41356c5e64 (opens in a new tab)
- git.kernel.org/stable/c/c1a0f5f1e5e7e98c36a362ec3d1fcfd9932931ed (opens in a new tab)
- git.kernel.org/stable/c/d82467c07b03a27c3c5469b62bb3b726305a80bb (opens in a new tab)
- git.kernel.org/stable/c/ac431d597a9bdfc2ba6b314813f29a6ef2b4a3bf (opens in a new tab)