CVE-2026-43405
published 2026-05-08CVE-2026-43405: In the Linux kernel, the following vulnerability has been resolved: libceph: Use u32 for non-negative values in ceph_monmap_decode() This patch fixes…
PriorityP341high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.49%
38.8th percentile
In the Linux kernel, the following vulnerability has been resolved:
libceph: Use u32 for non-negative values in ceph_monmap_decode()
This patch fixes unnecessary implicit conversions that change signedness
of blob_len and num_mon in ceph_monmap_decode().
Currently blob_len and num_mon are (signed) int variables. They are used
to hold values that are always non-negative and get assigned in
ceph_decode_32_safe(), which is meant to assign u32 values. Both
variables are subsequently used as unsigned values, and the value of
num_mon is further assigned to monmap->num_mon, which is of type u32.
Therefore, both variables should be of type u32. This is especially
relevant for num_mon. If the value read from the incoming message is
very large, it is interpreted as a negative value, and the check for
num_mon > CEPH_MAX_MON does not catch it. This leads to the attempt to
allocate a very large chunk of memory for monmap, which will most likely
fail. In this case, an unnecessary attempt to allocate memory is
performed, and -ENOMEM is returned instead of -EINVAL.
Affected
16 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | >= a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c < ee5588e2bc41acb73f6676c0520420c107cd0140 | ee5588e2bc41acb73f6676c0520420c107cd0140 |
| linux | linux | >= a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c < 86f7060cd638d6eb042e8ed780fb83a59ca0dcb3 | 86f7060cd638d6eb042e8ed780fb83a59ca0dcb3 |
| linux | linux | >= a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c < 5f2806684b05bd24d05c091083b8e2517ba8ffac | 5f2806684b05bd24d05c091083b8e2517ba8ffac |
| linux | linux | >= a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c < b268984ae88cb0dcd7a8e8263962c748448e26e8 | b268984ae88cb0dcd7a8e8263962c748448e26e8 |
| linux | linux | >= a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c < ba0a4df8c563536857dcbf7b4dbd0f2a15f57ace | ba0a4df8c563536857dcbf7b4dbd0f2a15f57ace |
| linux | linux | >= a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c < 08bc6173fd611ad5a40f472bf5f15b92aea0fe40 | 08bc6173fd611ad5a40f472bf5f15b92aea0fe40 |
| linux | linux | >= a5cbd5fc22d5043a8a76e15d75d031fe24d1f69c < 770444611f047dbfd4517ec0bc1b179d40c2f346 | 770444611f047dbfd4517ec0bc1b179d40c2f346 |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 5.11 < 5.15.203 | 5.15.203 |
| linux | linux_kernel | >= 5.16 < 6.1.167 | 6.1.167 |
| linux | linux_kernel | >= 6.13 < 6.18.19 | 6.18.19 |
| linux | linux_kernel | >= 6.19 < 6.19.9 | 6.19.9 |
| linux | linux_kernel | >= 6.2 < 6.6.130 | 6.6.130 |
| linux | linux_kernel | >= 6.7 < 6.12.78 | 6.12.78 |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vendor_redhat7.0MEDIUM
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Red Hat
kernel: libceph: Use u32 for non-negative values in ceph_monmap_decode()
vendor_redhat·2026-05-08·CVSS 7.0
CVE-2026-43405 [MEDIUM] CWE-681 kernel: libceph: Use u32 for non-negative values in ceph_monmap_decode()
kernel: libceph: Use u32 for non-negative values in ceph_monmap_decode()
A flaw was found in the libceph component of the Linux kernel. This vulnerability occurs in the ceph_monmap_decode() function due to incorrect handling of non-negative values, where int variables are used instead of u32 for blob_len and num_mon. An attacker could exploit this by sending a specially crafted message with an excessively large num_mon value. This could lead to an attempt to allocate a very large amount of memory, resulting in a Denial of Service (DoS) condition.
Package: kernel (Red Hat Enterprise Linux 10) - Affected
Package: kernel (Red Hat Enterprise Linux 6) - Not affected
Package: kernel (Red Hat Enterprise Linux 7) - Affected
Package: kernel-rt (Red Hat Enterprise Linux 7) - Affected
Package:
VulDB
Linux Kernel up to 6.19.8 ceph_monmap_decode data authenticity
vuldb·2026-05-22·CVSS 7.5
CVE-2026-43405 [HIGH] Linux Kernel up to 6.19.8 ceph_monmap_decode data authenticity
A vulnerability labeled as critical has been found in Linux Kernel up to 6.19.8. Impacted is the function ceph_monmap_decode. Such manipulation leads to insufficient verification of data authenticity.
This vulnerability is documented as CVE-2026-43405. The attack requires being on the local network. There is not any exploit available.
The affected component should be upgraded.
GHSA
GHSA-5r63-pv2h-4jqg: In the Linux kernel, the following vulnerability has been resolved:
libceph: Use u32 for non-negative values in ceph_monmap_decode()
This patch fixe
ghsa_unreviewed·2026-05-08
CVE-2026-43405 GHSA-5r63-pv2h-4jqg: In the Linux kernel, the following vulnerability has been resolved:
libceph: Use u32 for non-negative values in ceph_monmap_decode()
This patch fixe
In the Linux kernel, the following vulnerability has been resolved:
libceph: Use u32 for non-negative values in ceph_monmap_decode()
This patch fixes unnecessary implicit conversions that change signedness
of blob_len and num_mon in ceph_monmap_decode().
Currently blob_len and num_mon are (signed) int variables. They are used
to hold values that are always non-negative and get assigned in
ceph_decode_32_safe(), which is meant to assign u32 values. Both
variables are subsequently used as unsigned values, and the value of
num_mon is further assigned to monmap->num_mon, which is of type u32.
Therefore, both variables should be of type u32. This is especially
relevant for num_mon. If the value read from the incoming message is
very large, it is interpreted as a negative value, and the check
No detection rules found.
No public exploits indexed.
https://git.kernel.org/stable/c/08bc6173fd611ad5a40f472bf5f15b92aea0fe40https://git.kernel.org/stable/c/5f2806684b05bd24d05c091083b8e2517ba8ffachttps://git.kernel.org/stable/c/770444611f047dbfd4517ec0bc1b179d40c2f346https://git.kernel.org/stable/c/86f7060cd638d6eb042e8ed780fb83a59ca0dcb3https://git.kernel.org/stable/c/b268984ae88cb0dcd7a8e8263962c748448e26e8https://git.kernel.org/stable/c/ba0a4df8c563536857dcbf7b4dbd0f2a15f57acehttps://git.kernel.org/stable/c/ee5588e2bc41acb73f6676c0520420c107cd0140
2026-05-08
Published