VulnerabilityPublished 25 Sep 2026Updated 19 Oct 2026

CVE-2026-98031: Linux kernel · nexthop: Initialize extack in remove_nh_grp_entry()

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in d80677ad7aa5bebfccfd58caa4852b65abe70561 : 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 d80677ad7aa5bebfccfd58caa4852b65abe70561, d643cea4248668dc493c513aa7cbc6505eb1a4a9, 704319510af2179cf03955747d714ab291075c25 +4

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Sep 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 to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 833a1065eeb14437a9a0dfa9dad06ea09894e0b5, < d80677ad7aa5bebfccfd58caa4852b65abe70561	Fixed in d80677ad7aa5bebfccfd58caa4852b65abe70561
LinuxLinux	Affected ≥ 833a1065eeb14437a9a0dfa9dad06ea09894e0b5, < d643cea4248668dc493c513aa7cbc6505eb1a4a9	Fixed in d643cea4248668dc493c513aa7cbc6505eb1a4a9
LinuxLinux	Affected ≥ 833a1065eeb14437a9a0dfa9dad06ea09894e0b5, < 704319510af2179cf03955747d714ab291075c25	Fixed in 704319510af2179cf03955747d714ab291075c25
LinuxLinux	Affected ≥ 833a1065eeb14437a9a0dfa9dad06ea09894e0b5, < 35d9ec61466109ef0c2de87067338d929f629527	Fixed in 35d9ec61466109ef0c2de87067338d929f629527
LinuxLinux	Affected ≥ 833a1065eeb14437a9a0dfa9dad06ea09894e0b5, < 030c878eaedf0449e2b5401a0a0146d0afcc645e	Fixed in 030c878eaedf0449e2b5401a0a0146d0afcc645e
LinuxLinux	Affected ≥ 833a1065eeb14437a9a0dfa9dad06ea09894e0b5, < 17acbcd4c5a6ca3dd3f9e52eb203c9175bde609a	Fixed in 17acbcd4c5a6ca3dd3f9e52eb203c9175bde609a

AI-suggested

A fix is available and has been applied in the Linux kernel commits identified by the fixedVersions hashes. Users should update their Linux kernel to a version including these commits to remediate the issue.

Description

A vulnerability in the Linux kernel's nexthop component was fixed by initializing the extack variable in the remove_nh_grp_entry() function. The flaw involved dereferencing an uninitialized stack pointer when extack was not set by listeners during error handling, potentially causing instability or crashes.

Impact

The vulnerability could cause kernel instability or crashes due to dereferencing an uninitialized pointer during error handling in the nexthop group removal process. There is no indication of remote code execution or privilege escalation. No known exploits in the wild have been reported.

Summary

The Linux kernel's nexthop subsystem had a vulnerability where the remove_nh_grp_entry() function printed an extack message without initializing extack. Since listeners like netdevsim and mlxsw do not always set an extack message on allocation failure, this led to dereferencing an uninitialized stack pointer. The issue was resolved by zero-initializing extack, consistent with prior fixes in related nexthop code.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 12:53 UTC

Technical details

References

Community reviews

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