Kernel fault via uninitialized extack pointer dereference
Published Sep 25, 2026 · Updated Sep 25, 2026
Use of an uninitialized value in Linux 5.11 and affected commit ranges allows attackers to trigger a kernel pointer dereference. remove_nh_grp_entry() reads extack._msg after a listener replacement error without first initializing extack, and failing listeners need not set a message. Reachability requires a listener failure while replacing a reduced nexthop group; the record does not state whether the fault causes an oops or a system crash.
Summary
What happened
Use of an uninitialized value in Linux 5.11 and affected commit ranges allows attackers to trigger a kernel pointer dereference. remove_nh_grp_entry() reads extack._msg after a listener replacement error without first initializing extack, and failing listeners need not set a message. Reachability requires a listener failure while replacing a reduced nexthop group; the record does not state whether the fault causes an oops or a system crash.
The record
- CVE
- CVE-2026-98031
- Published
- Sep 25, 2026
- Updated
- Sep 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 25, 2026CVE publishedPublication date reported by the CVE source.
- Sep 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.11
- Affected versionversion=833a1065eeb14437a9a0dfa9dad06ea09894e0b5 <030c878eaedf0449e2b5401a0a0146d0afcc645e
- Affected versionversion=833a1065eeb14437a9a0dfa9dad06ea09894e0b5 <5bd9e4e7cdaa03879e9b73b12ab52cceb1edd55b
- Affected versionversion=833a1065eeb14437a9a0dfa9dad06ea09894e0b5 <d643cea4248668dc493c513aa7cbc6505eb1a4a9
- Affected versionversion=833a1065eeb14437a9a0dfa9dad06ea09894e0b5 <d80677ad7aa5bebfccfd58caa4852b65abe70561
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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