What is CVE-2026-52956?

CVE-2026-52956 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10, classified as a Out-of-bounds Read flaw (CWE-125), affecting Linux kernel versions from 4.9.6 onward and patched in 7.0.10 and 7.1. CVE-2026-52956 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-52956?

CVE-2026-52956 has a CVSS score of 7.5 out of 10, rated High severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-52956?

Yes, CVE-2026-52956 has been patched. Fixed versions include 7.0.10 and 7.1. If you are running Linux kernel 4.9.6 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-52956 actively exploited?

CVE-2026-52956 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Out-of-bounds Read (CWE-125)?

The product reads data past the end or before the beginning of the intended buffer. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/125.html

CVE-2026-52956

High

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.

Package Linux Kernel

Published 2026-06-24

Last modified 2026-07-14

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.5

out of 10

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-125

CVE-2026-52956 is a Out-of-bounds Read vulnerability

What is Out-of-bounds Read?

The product reads data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

Affected versions

Linux kernel versions 4.9.6, 4.10 and later are affected. Fixed in 7.0.10, 7.1 and their respective stable series.

Affected from

≥ 4.9.6 ≥ 4.10

Fixed in

✓ 7.0.10 7.0.x ✓ 7.1

References

2 total

Kernel Git
https://git.kernel.org/stable/c/821365487aa58d06bda65c676ba215d506ba9768

Patch
Kernel Git
https://git.kernel.org/stable/c/c7e9b53aebe401970f1b5f5a01b4e021b18e8bb2

Patch

Details

CVE ID CVE-2026-52956

Severity High

CVSS score 7.5 / 10

CVSS version 3.1

Published 2026-06-24

Modified 2026-07-14

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-52956?

CVE-2026-52956 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 , classified as an Out-of-bounds Read flaw (CWE-125) . It affects Linux kernel versions from 4.9.6 onward and has been patched in 7.0.10 and 7.1. CVE-2026-52956 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-52956?

CVE-2026-52956 has a CVSS score of 7.5 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-52956?

Yes. CVE-2026-52956 has been patched. Fixed versions include 7.0.10 and 7.1. If you are running Linux kernel 4.9.6 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-52956 actively exploited?

No. CVE-2026-52956 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.