Critical 9.8Published Jun 24, 2026

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

Updated under an hour ago (Oct 30, 2026, 3:10 AM ET)

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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: 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-131
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from f24e9980eb860d8600cbe5ef3d2fd9295320d229 before 6e70ef53e818c53eab28d7b0026b7fd03dddaba5; from f24e9980eb860d8600cbe5ef3d2fd9295320d229 before ebe76d58a48a48031b98543d86c4cd30a825b622; from f24e9980eb860d8600cbe5ef3d2fd9295320d229 before 3f42508191e129ee6b5ea96578d5cab14f2a013a; from f24e9980eb860d8600cbe5ef3d2fd9295320d229 before ea0d42137f0c06da71e37ffc647aab4c5309599a; from f24e9980eb860d8600cbe5ef3d2fd9295320d229 before cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5; from f24e9980eb860d8600cbe5ef3d2fd9295320d229 before 0f3604cbe4df14c5e58288ac9f57511e726a222d; from f24e9980eb860d8600cbe5ef3d2fd9295320d229 before fb176a99e4c1a5a8448a83d83d3606203ba81faa; from f24e9980eb860d8600cbe5ef3d2fd9295320d229 before 4c79fc2d598694bda845b46229c9d48b65042970	CNA record
Red Hat Red Hat Enterprise Linux 10 redhat:enterprise_linux	10	CISA ADP
linux linux_kernel linux:linux_kernel	from 2.6.34.1 before 5.10.258; from 5.11 before 5.15.209; from 5.16 before 6.1.175; from 6.2 before 6.6.141; from 6.7 before 6.12.91; from 6.13 before 6.18.33; from 6.19 before 7.0.10; 2.6.34; and 9 more ranges	NVD

References

References

https://git.kernel.org/stable/c/6e70ef53e818c53eab28d7b0026b7fd03dddaba5	patch
https://git.kernel.org/stable/c/ebe76d58a48a48031b98543d86c4cd30a825b622	patch
https://git.kernel.org/stable/c/3f42508191e129ee6b5ea96578d5cab14f2a013a	patch
https://git.kernel.org/stable/c/ea0d42137f0c06da71e37ffc647aab4c5309599a	patch
https://git.kernel.org/stable/c/cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5	patch
https://git.kernel.org/stable/c/0f3604cbe4df14c5e58288ac9f57511e726a222d	patch
https://git.kernel.org/stable/c/fb176a99e4c1a5a8448a83d83d3606203ba81faa	patch
https://git.kernel.org/stable/c/4c79fc2d598694bda845b46229c9d48b65042970	patch
https://access.redhat.com/security/cve/CVE-2026-52955	third-party-advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2492328	third-party-advisory
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.