Skip to main content
VulnerabilityPublished Updated

CVE-2026-52955: Linux kernel · libceph: Fix potential out-of-bounds access in crush_decode()

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 9.8 Critical · fixed in fb176a99e4c1a5a8448a83d83d3606203ba81faa : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 17:30 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 31% 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 fb176a99e4c1a5a8448a83d83d3606203ba81faa, ebe76d58a48a48031b98543d86c4cd30a825b622, ea0d42137f0c06da71e37ffc647aab4c5309599a +5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 24 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ f24e9980eb860d8600cbe5ef3d2fd9295320d229, < fb176a99e4c1a5a8448a83d83d3606203ba81faa
Fixed in
  • fb176a99e4c1a5a8448a83d83d3606203ba81faa
LinuxLinuxAffected
  • ≥ f24e9980eb860d8600cbe5ef3d2fd9295320d229, < ebe76d58a48a48031b98543d86c4cd30a825b622
Fixed in
  • ebe76d58a48a48031b98543d86c4cd30a825b622
LinuxLinuxAffected
  • ≥ f24e9980eb860d8600cbe5ef3d2fd9295320d229, < ea0d42137f0c06da71e37ffc647aab4c5309599a
Fixed in
  • ea0d42137f0c06da71e37ffc647aab4c5309599a
LinuxLinuxAffected
  • ≥ f24e9980eb860d8600cbe5ef3d2fd9295320d229, < cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5
Fixed in
  • cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5
LinuxLinuxAffected
  • ≥ f24e9980eb860d8600cbe5ef3d2fd9295320d229, < 6e70ef53e818c53eab28d7b0026b7fd03dddaba5
Fixed in
  • 6e70ef53e818c53eab28d7b0026b7fd03dddaba5
LinuxLinuxAffected
  • ≥ f24e9980eb860d8600cbe5ef3d2fd9295320d229, < 4c79fc2d598694bda845b46229c9d48b65042970
Fixed in
  • 4c79fc2d598694bda845b46229c9d48b65042970

Description

In the Linux kernel, the following vulnerability has been resolved: libceph: Fix potential out-of-bounds access in crush_decode() A message of type CEPH_MSG_OSD_MAP containing a crush map with at least one bucket has two fields holding the bucket algorithm. If the values in these two fields differ, an out-of-bounds access can occur. This is the case because the first algorithm field (alg) is used to allocate the correct amount of memory for a bucket of this type, while the second algorithm field inside the bucket (b->alg) is used in the subsequent processing. This patch fixes the issue by adding a check that compares alg and b->alg and aborts the processing in case they differ. Furthermore, b->alg is set to 0 in this case, because the destruction of the crush map also uses this field to determine the bucket type, which can again result in an out-of-bounds access when trying to free the memory pointed to by the fields of the bucket. To correctly free the memory allocated for the bucket in such a case, the corresponding call to kfree is moved from the algorithm-specific crush_destroy_bucket functions to the generic crush_destroy_bucket().

References

Community reviews

Loading reviews…