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Fencer Vulns
high 7.5

CVE-2026-74750 json

ovpn: defer key slot crypto freeing to workqueue

published 2026-08-26 2 mo ago modified 2026-10-15 25 d ago also EUVD-2026-66580

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

ovpn: defer key slot crypto freeing to workqueue

Key slots are released through a kref and the existing release path frees the AEAD transforms from an RCU callback. That is not safe for all crypto implementations: crypto_free_aead can sleep, for example when an async or hardware implementation has teardown work to complete.

Use queue_rcu_work for key-slot release. This keeps the RCU grace period needed by lockless key-slot readers, but runs the actual crypto teardown from workqueue context where sleeping is allowed. Once the rcu_work callback runs, pre-existing RCU readers are gone, and the final kref put already proves that no transform user remains, so the worker can release the AEAD transforms and free the slot directly.

The previous patch drains ovpn_wq during module exit, so queued key-slot teardown work cannot outlive module text.

Patch / fix

  • Linux Linux 6.18.57, 7.1.10, 7.2
  • linux Debian 14 7.1.10-1

debian advisories DEBIAN-CVE-2026-74750

  • linux Ubuntu 26.04 LTS 7.0.0-42.42
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
  • linux-ibm Ubuntu 26.04 LTS 7.0.0-1017.17
  • linux-riscv Ubuntu 26.04 LTS 7.0.0-42.42.1
  • linux-oracle Ubuntu 26.04 LTS 7.0.0-1015.16
  • linux-hwe-7.0 Ubuntu 24.04 LTS 7.0.0-42.42~24.04.1
  • linux-oem-7.0 Ubuntu 26.04 LTS 7.0.0-1017.17

ubuntu advisories UBUNTU-CVE-2026-74750

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-74750 updated cvss 5.5

kernel: ovpn: defer key slot crypto freeing to workqueue

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.