PT-2025-10068 · Linux+5 · Linux Kernel+5

Pumpkin Chang · Published 2025-02-12 · Updated 2026-04-20 · CVE-2025-21836

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The Linux kernel has a flaw within the io uring/kbuf subsystem. Specifically, the IORING REGISTER PBUF RING function can reuse an old struct io buffer list if it was created for a legacy selected buffer and has been emptied. This violates the requirement that most of the field should remain stable after publication.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Use After Free

Allocation of Resources Without Limits

Weakness Enumeration

CWE-416

CWE-770

Related Identifiers

BDU:2026-02848

CVE-2025-21836

ECHO-F35C-D0D3-8C20

OESA-2025-1446

OESA-2025-1450

OPENSUSE-SU-2025_01614-1

OPENSUSE-SU-2025_01707-1

SUSE-SU-2025:01614-1

SUSE-SU-2025:01707-1

SUSE-SU-2025:01919-1

SUSE-SU-2025:01951-1

SUSE-SU-2025:01964-1

SUSE-SU-2025:01967-1

SUSE-SU-2025:20192-1

SUSE-SU-2025:20206-1

SUSE-SU-2025:20270-1

SUSE-SU-2025:20283-1

SUSE-SU-2025_01614-1

SUSE-SU-2025_01707-1

SUSE-SU-2025_01951-1

SUSE-SU-2025_01964-1

SUSE-SU-2025_01967-1

USN-7521-1

USN-7521-2

USN-7521-3

USN-7703-1

USN-7703-2

USN-7703-3

USN-7703-4

USN-7719-1

USN-7737-1

Affected Products

Astra Linux

Debian

Linuxmint

Linux Kernel

Suse

Ubuntu

References · 1965

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21836.json · Exploit
• https://ubuntu.com/security/CVE-2024-57997 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-21780 · Security Note
• https://ubuntu.com/security/CVE-2025-21871 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-21941 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2025-21927 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2025-21914 · Security Note
• https://ubuntu.com/security/CVE-2025-21864 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-21791 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-21820 · Vendor Advisory
• https://ubuntu.com/security/CVE-2024-58082 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-21742 · Vendor Advisory
• https://ubuntu.com/security/CVE-2024-58090 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-7521-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-21836 · Vendor Advisory