CVE-2026-52955
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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().
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.38% probability · 31th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125, CWE-131
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/0f3604cbe4df14c5e58288ac9f57511e726a222dPatch
- https://git.kernel.org/stable/c/3f42508191e129ee6b5ea96578d5cab14f2a013aPatch
- https://git.kernel.org/stable/c/4c79fc2d598694bda845b46229c9d48b65042970Patch
- https://git.kernel.org/stable/c/6e70ef53e818c53eab28d7b0026b7fd03dddaba5Patch
- https://git.kernel.org/stable/c/cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5Patch
- https://git.kernel.org/stable/c/ea0d42137f0c06da71e37ffc647aab4c5309599aPatch
- https://git.kernel.org/stable/c/ebe76d58a48a48031b98543d86c4cd30a825b622Patch
- https://git.kernel.org/stable/c/fb176a99e4c1a5a8448a83d83d3606203ba81faaPatch
- https://access.redhat.com/security/cve/CVE-2026-52955Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2492328Third Party Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52955.jsonThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.