CVE-2025-21836
7.8 · HIGHOverview
CVE-2025-21836 is a high-severity vulnerability affecting linux linux_kernel. It was published on March 7, 2025 and has a CVSS 3.1 base score of 7.8 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.8, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical Description
In the Linux kernel, the following vulnerability has been resolved:
io_uring/kbuf: reallocate buf lists on upgrade
IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it
was created for legacy selected buffer and has been emptied. It violates
the requirement that most of the field should stay stable after publish.
Always reallocate it instead.
Remediation
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| linux | linux_kernel | >= 5.19, < 6.6.79 | Affected |
References
Frequently Asked Questions
What is CVE-2025-21836?
CVE-2025-21836 is a high-severity vulnerability affecting linux linux_kernel. It was published on March 7, 2025 and has a CVSS 3.1 base score of 7.8 (HIGH).
How severe is CVE-2025-21836?
This vulnerability has a CVSS 3.1 base score of 7.8, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2025-21836?
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-21836?
CyberStrike's AI-powered security agents can automatically detect CVE-2025-21836 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
AI-driven PR review catches vulnerable dependencies before they ship.
Browser-based exploitation validates findings with real proof-of-concept.
Related HIGH CVEs from 2025
View all →HCL MyXalytics is affected by out-of-band resource load (HTTP) vulnerability. An attacker can deplo
The NextEPC MME <= 1.0.1 (fixed in commit a8492c9c5bc0a66c6999cb5a263545b32a4109df) contains a stack
A flaw was found in the Red Hat Advanced Cluster Security (RHACS) portal. When rendering a table vie
A Stored Cross-Site Scripting (XSS) vulnerability exists in the chat file upload functionality of op
A: Improper Neutralization of Input During Web Page Generation vulnerability in SUSE rancher allows
Mbed TLS before 3.6.4 allows a use-after-free in certain situations of applications that are develop
In iperf before 3.19.1, net.c has a buffer overflow when --skip-rx-copy is used (for MSG_TRUNC in re
Missing authorization in Ivanti Connect Secure before 22.7R2.9 or 22.8R2, Ivanti Policy Secure befor
Memory corruptions can be remotely triggered in the Control-M/Agent when SSL/TLS communication is co
Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerab
Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerab
An issue in Orban Optimod 5950, Optimod 5950HD, Optimod 5750, Optimod 5750HD, Optimod Trio Optimod v