VulnerabilityPublished 6 Oct 2026Updated 19 Oct 2026

CVE-2026-98235: Linux kernel · net/sched: act_api: release tail references on DELACTION failure

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in 57b477e46ef2df3483f3488cc713c61c4b384aab : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 57b477e46ef2df3483f3488cc713c61c4b384aab, 9eaba16f1b6ee19b249e6afd82c27f958d441458, 6e05e46fa821a5c1b281355f1f622ac76cb6080a +1

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Linux kernel to 57b477e46ef2df3483f3488cc713c61c4b384aab, 9eaba16f1b6ee19b249e6afd82c27f958d441458, 6e05e46fa821a5c1b281355f1f622ac76cb6080a or 1be63e4579af408d596f0f3165faf1a880631d3b.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ a0e947c9ccffe47d45aca793d9e7fe4f4494e381, < 57b477e46ef2df3483f3488cc713c61c4b384aab	Fixed in 57b477e46ef2df3483f3488cc713c61c4b384aab
LinuxLinux	Affected ≥ a0e947c9ccffe47d45aca793d9e7fe4f4494e381, < 9eaba16f1b6ee19b249e6afd82c27f958d441458	Fixed in 9eaba16f1b6ee19b249e6afd82c27f958d441458
LinuxLinux	Affected ≥ a0e947c9ccffe47d45aca793d9e7fe4f4494e381, < 6e05e46fa821a5c1b281355f1f622ac76cb6080a	Fixed in 6e05e46fa821a5c1b281355f1f622ac76cb6080a
LinuxLinux	Affected ≥ a0e947c9ccffe47d45aca793d9e7fe4f4494e381, < 1be63e4579af408d596f0f3165faf1a880631d3b	Fixed in 1be63e4579af408d596f0f3165faf1a880631d3b
LinuxLinux	Affected =6.8	Fixed in–

AI-suggested

A fix is available and has been applied in the Linux kernel. Users should update to the fixed versions identified by the commits 57b477e46ef2df3483f3488cc713c61c4b384aab, 9eaba16f1b6ee19b249e6afd82c27f958d441458, 6e05e46fa821a5c1b281355f1f622ac76cb6080a, and 1be63e4579af408d596f0f3165faf1a880631d3b. No additional mitigation actions are indicated.

Description

A vulnerability in the Linux kernel's net/sched subsystem involving improper release of references on DELACTION failure has been fixed. The issue occurs when a batched RTM_DELACTION request partially processes actions, leading to leaked references for unprocessed actions. This can cause later deletions of unbound actions to succeed without actually removing them, potentially causing resource leaks.

Impact

This vulnerability causes reference leaks in the kernel's traffic control action subsystem, which may lead to resource exhaustion or inconsistent state in action management. While it does not directly enable code execution or privilege escalation, the improper cleanup can degrade system stability or reliability over time.

Summary

The Linux kernel's net/sched act_api component improperly handles reference counting during batched RTM_DELACTION requests. When deletion of an action fails, the iterator used to release remaining references stops prematurely at the first NULL slot, leaking references on subsequent actions. This flaw allows later deletion attempts to return success without removing the action from the IDR, causing stale references. The fix involves modifying tcf_action_put_many() to walk the entire array and skip NULL slots to properly release all references.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 12:08 UTC

Technical details

References

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