CVE-2026-52955
Linux Kernel out-of-bounds read
- Published24 Jun 2026
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 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HAffected products
Remediation
- https://git.kernel.org/stable/c/0f3604cbe4df14c5e58288ac9f57511e726a222d
- https://git.kernel.org/stable/c/3f42508191e129ee6b5ea96578d5cab14f2a013a
- https://git.kernel.org/stable/c/4c79fc2d598694bda845b46229c9d48b65042970
- https://git.kernel.org/stable/c/6e70ef53e818c53eab28d7b0026b7fd03dddaba5
- https://git.kernel.org/stable/c/cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5
- https://git.kernel.org/stable/c/ea0d42137f0c06da71e37ffc647aab4c5309599a
References
- https://access.redhat.com/security/cve/CVE-2026-52955
- https://bugzilla.redhat.com/show_bug.cgi?id=2492328
- https://git.kernel.org/stable/c/0f3604cbe4df14c5e58288ac9f57511e726a222d
- https://git.kernel.org/stable/c/3f42508191e129ee6b5ea96578d5cab14f2a013a
- https://git.kernel.org/stable/c/4c79fc2d598694bda845b46229c9d48b65042970
- https://git.kernel.org/stable/c/6e70ef53e818c53eab28d7b0026b7fd03dddaba5
- https://git.kernel.org/stable/c/cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5
- https://git.kernel.org/stable/c/ea0d42137f0c06da71e37ffc647aab4c5309599a
- https://git.kernel.org/stable/c/ebe76d58a48a48031b98543d86c4cd30a825b622
- https://git.kernel.org/stable/c/fb176a99e4c1a5a8448a83d83d3606203ba81faa
and 1 more references
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2026-52955 being actively exploited?
CVE-2026-52955 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.51%.
How severe is CVE-2026-52955?
CVE-2026-52955 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.51% probability of exploitation.
Which products are affected by CVE-2026-52955?
Affected products include Linux Kernel.
How do I fix CVE-2026-52955?
Upgrade affected software to a fixed version, for example Linux Kernel 5.10.258 or later, then confirm no affected versions remain in your inventory.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-52955 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.