VulnerabilityPublished 18 Oct 2026

CVE-2026-98559: Linux kernel · net/smc: fix UAF on lgr list traversal in smcr_port_err()

Source GCVE Database

Authoritative record:CVE-2026-98559· High

Not known to be exploited · fixed in a9b968e42690d784c241a0761c10253271f7df5d : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in a9b968e42690d784c241a0761c10253271f7df5d, 61cb282fe97b3b0ba32ca09417a693162bf4ae3f, 34bcf11cd2528ae00bb6d764d808083c66824277 +4

Exploitation evidence

Disclosed: evidence found.
CVE published 18 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.

ghsa-4x5q-83g5-68jv

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 541afa10c126b6c22c2a805a559c70cc41fd156e, < a9b968e42690d784c241a0761c10253271f7df5d	Fixed in a9b968e42690d784c241a0761c10253271f7df5d
LinuxLinux	Affected ≥ 541afa10c126b6c22c2a805a559c70cc41fd156e, < 61cb282fe97b3b0ba32ca09417a693162bf4ae3f	Fixed in 61cb282fe97b3b0ba32ca09417a693162bf4ae3f
LinuxLinux	Affected ≥ 541afa10c126b6c22c2a805a559c70cc41fd156e, < 34bcf11cd2528ae00bb6d764d808083c66824277	Fixed in 34bcf11cd2528ae00bb6d764d808083c66824277
LinuxLinux	Affected ≥ 541afa10c126b6c22c2a805a559c70cc41fd156e, < 3d65a2eb4449fc9658fb860dea893025d028d90e	Fixed in 3d65a2eb4449fc9658fb860dea893025d028d90e
LinuxLinux	Affected ≥ 541afa10c126b6c22c2a805a559c70cc41fd156e, < 3d35f069e1c119992000d51236dbe54da2d4e61e	Fixed in 3d35f069e1c119992000d51236dbe54da2d4e61e
LinuxLinux	Affected ≥ 541afa10c126b6c22c2a805a559c70cc41fd156e, < 0edcc4284392b28826b5d37532b366b291e6e0fa	Fixed in 0edcc4284392b28826b5d37532b366b291e6e0fa

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AI-suggested

A fix has been implemented in the Linux kernel source to hold the smc_lgr_list.lock during list traversal in smcr_port_err() and to adjust the call sequence in smc_ib_gid_check(). Users should update to the patched kernel versions once available. Patch status is not explicitly confirmed in the provided data; check the vendor advisory for current remediation guidance.

Description

A use-after-free (UAF) vulnerability in the Linux kernel's net/smc subsystem was resolved. The function smcr_port_err() traversed the smc_lgr_list.list without holding the necessary lock, allowing concurrent termination of an lgr object while it was still being accessed. This could lead to dereferencing freed memory. The fix involves holding the smc_lgr_list.lock during traversal and adjusting the call order in smc_ib_gid_check().

References

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