CVE-2026-52929
Description
A flaw was found in the Linux kernel's SCTP stream scheduler. When transient outgoing streams are denied and torn down, the kernel fails to reclaim scheduler-specific metadata before an algorithm switch (e.g., WFQ to PRIO). The orphaned state - including internal accounting fields - becomes reachable through the new scheduler's accessors, allowing an unprivileged local attacker to read arbitrary kernel memory and corrupt kernel objects via SCTP_STREAM_SCHEDULER_VALUE socket options. This can be leveraged for local privilege escalation to full root capabilities. A failed exploitation attempt may also crash the kernel, resulting in a Denial of Service (DoS).
Mitigation
To mitigate this issue, prevent the `sctp` kernel module from loading. Create a file named `/etc/modprobe.d/disable-sctp.conf` with the following content:
install sctp /bin/true
blacklist sctp
After creating the file, regenerate the initramfs and reboot the system for the changes to take effect. Applications or services that rely on the SCTP protocol cannot use this mitigation and should prioritize applying the fix.
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.8 | N/A | 7.5 |
| Attack Vector | Local | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | None |
| Integrity Impact | High | N/A | None |
| 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:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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