CVE-2026-52929

Description

In the Linux kernel, the following vulnerability has been resolved: sctp: stream: fully roll back denied add-stream state When ADD_OUT_STREAMS is denied, SCTP only shrinks the queued chunks and then lowers outcnt. That leaves removed stream metadata behind, so a later re-add can reuse a stale ext and hit a null-pointer dereference in the scheduler get path. Fix the rollback by tearing down the removed stream state the same way other stream resizes do. Unschedule the current scheduler state, drop the removed stream ext state with sctp_stream_outq_migrate(), and then reschedule the remaining streams. This keeps scheduler-private RR/FC/PRIO lists consistent while fully rolling back denied outgoing stream additions.

CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0039

Probability of exploitation

0.31%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/0cd2dc6dce8ca47212cd306ccd52eb315ef3cf85 https://git.kernel.org/stable/c/1c6773b8c081509dcd5cd2954f2b02c50c00f151 https://git.kernel.org/stable/c/39dc2b0eb5371a669ebc9ec6072b9184eac95418 https://git.kernel.org/stable/c/7dd9a42b044aad2dbe037db1c1e2943582485b44 https://git.kernel.org/stable/c/9662eb0401518f0b4681f10e7fbf688f504f24cf https://git.kernel.org/stable/c/a5f8a90ac9f77c678a9781c0a464b635e0d63e49 https://git.kernel.org/stable/c/a6724b7b812ac8793514a1d5938db5d9d29ae725 https://git.kernel.org/stable/c/d5ea0b3e261fcb2cfff142675516165244cab1da

Frequently Asked Questions

What is CVE-2026-52929? +

In the Linux kernel, the following vulnerability has been resolved: sctp: stream: fully roll back denied add-stream state When ADD_OUT_STREAMS is denied, SCTP only shrinks the queued chunks and then lowers outcnt. That leaves removed stream metadata behind, so a later re-add can reuse a stale ext and hit a null-pointer dereference in the scheduler get path. Fix the rollback by tearing down the removed stream state the same way other stream resizes do. Unschedule the current scheduler state, drop the removed stream ext state with sctp_stream_outq_migrate(), and then reschedule the remaining streams. This keeps scheduler-private RR/FC/PRIO lists consistent while fully rolling back denied outgoing stream additions. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-52929? +

CVE-2026-52929 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0039, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-52929? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.