Critical severity · published Jun 24, 2026
CVE-2026-52955
libceph: Fix potential out-of-bounds access in crush_decode()
9.8
CVSS
0.4%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 32% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
2.6.34.1 before 5.10.258; 5.11 before 5.15.209; 5.16 before 6.1.175; 6.2 before 6.6.141; 6.7 before 6.12.91; 6.13 before 6.18.33; +11 more · source: NVD
LI
Linux · Linux
f24e9980eb860d8600cbe5ef3d2fd9295320d229 before 6e70ef53e818c53eab28d7b0026b7fd03dddaba5; f24e9980eb860d8600cbe5ef3d2fd9295320d229 before ebe76d58a48a48031b98543d86c4cd30a825b622; f24e9980eb860d8600cbe5ef3d2fd9295320d229 before 3f42508191e129ee6b5ea96578d5cab14f2a013a; f24e9980eb860d8600cbe5ef3d2fd9295320d229 before ea0d42137f0c06da71e37ffc647aab4c5309599a; f24e9980eb860d8600cbe5ef3d2fd9295320d229 before cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5; f24e9980eb860d8600cbe5ef3d2fd9295320d229 before 0f3604cbe4df14c5e58288ac9f57511e726a222d; +3 more · source: vendor
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 7 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 9 · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-52955
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-52955
Patch
https://git.kernel.org/stable/c/0f3604cbe4df14c5e58288ac9f57511e726a222d
Patch
https://git.kernel.org/stable/c/3f42508191e129ee6b5ea96578d5cab14f2a013a
Patch
https://git.kernel.org/stable/c/4c79fc2d598694bda845b46229c9d48b65042970
Patch
https://git.kernel.org/stable/c/6e70ef53e818c53eab28d7b0026b7fd03dddaba5
Patch
https://git.kernel.org/stable/c/cceb10023e76bc89f3fe9238ebd0ccab0fc7c7c5
Patch
https://git.kernel.org/stable/c/ea0d42137f0c06da71e37ffc647aab4c5309599a
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