CVE Intelligence
High

CVE-2026-99054 — tipc: destroy topsrv workqueues before closing connections

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.

Published Oct 23, 2026 · Updated Oct 30, 2026 · Sources: CVE Program (cve.org) e CISA ADP, NIST National Vulnerability Database, GitHub Security Advisories · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.2% (30-day exploitation probability)+1
  • Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.16%
ahead of 5% of scored CVEs · Oct 30, 2026
Affects
Linux
Linux
CVSS base
7.8
High · 3 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux ≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f and < 7f796bb3b440d7f1b14c0e3b520462eb34f553af≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f and < da9c16568bc79140a54c1f5fcf07a0305df47b37≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f and < 0af8780bdfdfc91fb9127bddb9c48fab67dc9d9e≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f and < fb717c536af2aafeca520ff11d1e0f25f7ab8fa9≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f and < 3acdd44385bc7e2e57605e073691ce69cc5a960dversion 3.11≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f and < 09dbd610f78aaed65d7b379c270ce4090a8151ac≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f and < 21622e5ae8b232c2e64eb1adf5546cf078d2987d
and 1 more ≥ c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f and < 7167afaaaee37191f8b6afa0c91e0fef41460705
Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
7.8 CVSS 3.1 High 1.8 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
7.8 CVSS 3.1 High — — GitHub, Inc. via GitHub Security Advisories
7.8 CVSS 3.1 High — — Linux via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

EPSS over time FIRST

Oct 24, 2026 → Oct 30, 2026 · 7 reading(s) · max 0.21%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · linux/linux
    Oct 30, 2026 · CVE Program (cve.org) e CISA ADP
  • CVSS changed · 7.8
    Oct 24, 2026 · NIST National Vulnerability Database
  • Source status changed · Published → Received
    Oct 23, 2026 · NIST National Vulnerability Database
  • Record published
    Oct 23, 2026
  • Source status changed · → Published
    Oct 23, 2026 · CVE Program (cve.org) e CISA ADP
  • Record created in this database
    Oct 23, 2026 · CVE Program (cve.org) e CISA ADP
  • CVE published
    Oct 23, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 24, 2026 – Oct 30, 2026
  • 1× Official description updated · Oct 23, 2026 – Oct 23, 2026

References

10 on the record

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

  • CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 2d
  • CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 2d
  • CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 2d
  • CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 2d
  • CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 2d
  • CVE-2026-99210 accel/rocket: clear rdev on device init failure 2d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No CISA SSVC assessment.
  • No CWE classification.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-99054 is "tipc: destroy topsrv workqueues before closing connections", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.16% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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