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VulnerabilityPublished Updated

CVE-2026-99054: Linux kernel · tipc: destroy topsrv workqueues before closing connections

Source GCVE Database

0
Authoritative record:CVE-2026-99054· High 7.8

Not known to be exploited · CVSS 7.8 High · fixed in fb717c536af2aafeca520ff11d1e0f25f7ab8fa9 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in fb717c536af2aafeca520ff11d1e0f25f7ab8fa9, da9c16568bc79140a54c1f5fcf07a0305df47b37, 7f796bb3b440d7f1b14c0e3b520462eb34f553af +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 23 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f, < fb717c536af2aafeca520ff11d1e0f25f7ab8fa9
Fixed in
  • fb717c536af2aafeca520ff11d1e0f25f7ab8fa9
LinuxLinuxAffected
  • ≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f, < da9c16568bc79140a54c1f5fcf07a0305df47b37
Fixed in
  • da9c16568bc79140a54c1f5fcf07a0305df47b37
LinuxLinuxAffected
  • ≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f, < 7f796bb3b440d7f1b14c0e3b520462eb34f553af
Fixed in
  • 7f796bb3b440d7f1b14c0e3b520462eb34f553af
LinuxLinuxAffected
  • ≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f, < 3acdd44385bc7e2e57605e073691ce69cc5a960d
Fixed in
  • 3acdd44385bc7e2e57605e073691ce69cc5a960d
LinuxLinuxAffected
  • ≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f, < 0af8780bdfdfc91fb9127bddb9c48fab67dc9d9e
Fixed in
  • 0af8780bdfdfc91fb9127bddb9c48fab67dc9d9e
LinuxLinuxAffected
  • =3.11
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: tipc: destroy topsrv workqueues before closing connections tipc_topsrv_stop() closed subscriber connections while the topology server's send and receive workqueues were still running. Socket callbacks and subscription events could then queue more work, and in-flight send/recv work could drop the last connection reference during the conn_idr walk. That race produced several teardown failures: refcount_t addition on 0 from conn_get() on a connection whose release was blocked on idr_lock, a subsequent use-after-free in tipc_conn_close(), queue_work() on an already destroyed workqueue from the listener data-ready callback, and an RCU stall in tipc_topsrv_exit_net() while the walk spun under idr_lock. Clear srv->listener under idr_lock so it acts as a shutdown flag, skip queue_work() once it is NULL, destroy the workqueues to flush in-flight work, and only then close the remaining connections. Refuse tipc_conn_lookup() after that flag is cleared, and drop idr_lock when the teardown walk finds no connection, so an in-flight subscription event cannot pin idr_in_use while the walk holds the lock. v3 supersedes the narrower in-thread diff Tung Quang Nguyen posted on 2026-09-23. It keeps his teardown order and adds the lookup refusal and the empty-idr unlock.

References

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