CVE-2026-46323
Description
A flaw was found in the Linux kernel's Generic Receive Offload (GRO) networking subsystem. This vulnerability occurs when skb_gro_receive() attempts to merge zerocopy socket buffers (skbs) without properly managing page reference counts, specifically when the SKBFL_MANAGED_FRAG_REFS flag is set. An attacker could potentially exploit this to trigger a Use-After-Free (UAF) condition, which is a memory corruption vulnerability that can lead to system instability or potentially arbitrary code execution.
Statement
This is an Important flaw in the Linux kernel's Generic Receive Offload (GRO) networking subsystem. The vulnerability, a variant of Fragnesia, stems from improper management of page reference counts when merging zerocopy socket buffers. An attacker could exploit this Use-After-Free condition to achieve arbitrary code execution or cause system instability on affected Red Hat Enterprise Linux and OpenShift Container Platform systems.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.8 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability,Access Control
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands; Gain Privileges or Assume Identity; DoS: Crash, Exit, or Restart; Bypass Protection Mechanism
Clearly, write-what-where conditions can be used to write data to areas of memory outside the scope of a policy. Also, they almost invariably can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy. If the attacker can overwrite a pointer's worth of memory (usually 32 or 64 bits), they can redirect a function pointer to their own malicious code. Even when the attacker can only modify a single byte arbitrary code execution can be possible. Sometimes this is because the same problem can be exploited repeatedly to the same effect. Other times it is because the attacker can overwrite security-critical application-specific data -- such as a flag indicating whether the user is an administrator.
Integrity,Availability
Technical Impact: DoS: Crash, Exit, or Restart; Modify Memory
Many memory accesses can lead to program termination, such as when writing to addresses that are invalid for the current process.
Access Control,Other
Technical Impact: Bypass Protection Mechanism; Other
When the consequence is arbitrary code execution, this can often be used to subvert any other security service.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
