CVE-2026-46242
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Last Modified:
Description
A flaw was found in the Linux kernel's eventpoll mechanism. A Use-After-Free (UAF) vulnerability, where the system attempts to access memory after it has been freed, can occur during the removal of a file. A local attacker could exploit this race condition to corrupt memory, potentially leading to privilege escalation or arbitrary code execution. This allows an attacker to gain elevated control over the system.
Statement
A race in eventpoll ep_remove() can let a concurrent file release observe a transient cleared file f_ep state and skip the normal eventpoll_release_file cleanup path. In the epoll watches epoll case this can free the watched struct eventpoll while ep_remove() still uses list pointers that refer into that freed object, so hlist_del_rcu() can write into freed kmalloc memory. This is a use-after-free memory corruption issue rather than a pure crash or resource leak. For the CVSS the AC:H is selected because reliable triggering depends on a race window between ep_remove() and __fput(). The issue is not network reachable. Impact is at least a local denial of service via kernel crash and in worst case may allow confidentiality, integrity, and availability compromise due to kernel heap memory corruption. Keeping Moderate with CVSS 7.0, but could be increased to the Important if reproducer becomes available that shows LPE possibility.
RHEL 9.0 and 9.2 are not affected.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Additional information
- This content is not included.Bugzilla 2483519: kernel: eventpoll: fix ep_remove struct eventpoll / struct file UAF
- Content from cwe.mitre.org is not included.CWE-825: Expired Pointer Dereference
Affected Packages and Issued Red Hat Security Errata
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.
| Products / Services | Components | State | Errata |
|---|---|---|---|
| NVIDIA for RHEL 10 | kernel | Fixed | RHSA-2026:36186 |
| Red Hat Enterprise Linux 10 | kernel | Fixed | RHSA-2026:36541 |
| Red Hat Enterprise Linux 10.0 Extended Update Support | kernel | Fixed | RHSA-2026:39371 |
| Red Hat Enterprise Linux 6 | kernel | Not affected | |
| Red Hat Enterprise Linux 7 | kernel | Not affected | |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | |
| Red Hat Enterprise Linux 8 | kernel | Not affected | |
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | |
| Red Hat Enterprise Linux 9 | kernel | Fixed | This content is not included.RHSA-2026:36645 |
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected | |
| Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | kernel | Fixed | RHSA-2026:37729 |
| Red Hat Enterprise Linux 9.6 Extended Update Support | kernel | Fixed | RHSA-2026:38902 |
| Red Hat OpenShift Container Platform 4.20 | rhcos | Fixed | RHSA-2026:40787 |
| Red Hat OpenShift Container Platform 4.21 | rhcos | Fixed | RHSA-2026:40779 |
| Red Hat OpenShift Container Platform 4.22 | rhcos | Fixed | RHSA-2026:40764 |
Common Vulnerability Scoring System (CVSS) Score Details
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 Authorities (CNA) source for its products and services (see Red Hat classifications ).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| CVSS v3 Base Score | 7 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality Impact | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
CVSS v3 Vector
Red Hat CVSS:3.1/AV:L/AC:H/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
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
For more information, see https://access.redhat.com/solutions/762393.
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
- "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
- "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.
What can I do if my product is listed as "Will not fix"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
What can I do if my product is listed as "Fix deferred"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
- Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
My product is listed as "Out of Support Scope". What does this mean?
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