CVE-2026-52956
libceph: Fix potential out-of-bounds access in __ceph_x_decrypt()
Description
In the Linux kernel, the following vulnerability has been resolved: libceph: Fix potential out-of-bounds access in __ceph_x_decrypt() In __ceph_x_decrypt(), a part of the buffer p is interpreted as a ceph_x_encrypt_header, and the magic field of this struct is accessed. This happens without any guarantee that the buffer is large enough to hold this struct. The function parameter ciphertext_len represents the length of the ciphertext to decrypt and is guaranteed to be at most the remaining size of the allocated buffer p. However, this value is not necessarily greater than sizeof(ceph_x_encrypt_header). E.g., a message frame of type FRAME_TAG_AUTH_REPLY_MORE, that is just as long to hold the ciphertext at its end with a ciphertext_len of 8 or less, can trigger an out-of-bounds memory access when accessing hdr->magic. This patch fixes the issue by adding a check to ensure that the decrypted plaintext in the buffer is large enough to represent at least the ceph_x_encrypt_header.
INFO
Published Date :
June 24, 2026, 5:17 p.m.
Last Modified :
July 14, 2026, 4:43 p.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Validate buffer size before accessing header fields.
- Apply the provided kernel patch for libceph.
- Update the Linux kernel to the latest version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-52956.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/821365487aa58d06bda65c676ba215d506ba9768 | Patch |
| https://git.kernel.org/stable/c/c7e9b53aebe401970f1b5f5a01b4e021b18e8bb2 | Patch |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-52956 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-52956
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-52956 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-52956 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Jul. 14, 2026
Action Type Old Value New Value Added CWE CWE-125 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.10 up to (excluding) 7.0.10 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.9.6 up to (excluding) 4.10 Added Reference Type kernel.org: https://git.kernel.org/stable/c/821365487aa58d06bda65c676ba215d506ba9768 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/c7e9b53aebe401970f1b5f5a01b4e021b18e8bb2 Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 01, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': 'c7e9b53aebe401970f1b5f5a01b4e021b18e8bb2', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '821365487aa58d06bda65c676ba215d506ba9768', 'versionType': 'git'}, {'status': 'affected', 'version': '0', 'lessThan': '7.0.10', 'versionType': 'semver'}], 'programFiles': ['net/ceph/auth_x.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'unaffected', 'version': '7.0.10', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/ceph/auth_x.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'e15fd0a11db00fc7f470a9fc804657ec3f6d04a5', 'lessThan': 'c7e9b53aebe401970f1b5f5a01b4e021b18e8bb2', 'versionType': 'git'}, {'status': 'affected', 'version': 'e15fd0a11db00fc7f470a9fc804657ec3f6d04a5', 'lessThan': '821365487aa58d06bda65c676ba215d506ba9768', 'versionType': 'git'}, {'status': 'affected', 'version': '2982b9c92a66604ffb9fb2db54cf735133d1ef56', 'versionType': 'git'}, {'status': 'affected', 'version': '4.9.6', 'lessThan': '4.10', 'versionType': 'semver'}], 'programFiles': ['net/ceph/auth_x.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.10'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.10', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.0.10', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/ceph/auth_x.c'], 'defaultStatus': 'affected'}] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 28, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 24, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': 'c7e9b53aebe401970f1b5f5a01b4e021b18e8bb2', 'versionType': 'git'}, {'status': 'affected', 'version': '1da177e4c3f41524e886b7f1b8a0c1fc7321cac2', 'lessThan': '821365487aa58d06bda65c676ba215d506ba9768', 'versionType': 'git'}, {'status': 'affected', 'version': '0', 'lessThan': '7.0.10', 'versionType': 'semver'}], 'programFiles': ['net/ceph/auth_x.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'unaffected', 'version': '7.0.10', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/ceph/auth_x.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: libceph: Fix potential out-of-bounds access in __ceph_x_decrypt() In __ceph_x_decrypt(), a part of the buffer p is interpreted as a ceph_x_encrypt_header, and the magic field of this struct is accessed. This happens without any guarantee that the buffer is large enough to hold this struct. The function parameter ciphertext_len represents the length of the ciphertext to decrypt and is guaranteed to be at most the remaining size of the allocated buffer p. However, this value is not necessarily greater than sizeof(ceph_x_encrypt_header). E.g., a message frame of type FRAME_TAG_AUTH_REPLY_MORE, that is just as long to hold the ciphertext at its end with a ciphertext_len of 8 or less, can trigger an out-of-bounds memory access when accessing hdr->magic. This patch fixes the issue by adding a check to ensure that the decrypted plaintext in the buffer is large enough to represent at least the ceph_x_encrypt_header. Added Reference https://git.kernel.org/stable/c/821365487aa58d06bda65c676ba215d506ba9768 Added Reference https://git.kernel.org/stable/c/c7e9b53aebe401970f1b5f5a01b4e021b18e8bb2