Incorrect callback execution via stale shadow-stack headers
Published Oct 18, 2026 · Updated Oct 18, 2026
Incorrect callback dispatch in Linux 7.1 allows attackers to invoke duplicate or skipped fprobe exit handlers via stale stack headers. fprobe_fgraph_entry() leaves unused reserved storage unterminated, and fprobe_return() interprets old contents as current headers. The failure requires active fprobes with exit handlers and partially filled reservations; broader security consequences and attacker privileges are not established.
Summary
What happened
Incorrect callback dispatch in Linux 7.1 allows attackers to invoke duplicate or skipped fprobe exit handlers via stale stack headers. fprobe_fgraph_entry() leaves unused reserved storage unterminated, and fprobe_return() interprets old contents as current headers. The failure requires active fprobes with exit handlers and partially filled reservations; broader security consequences and attacker privileges are not established.
The record
- CVE
- CVE-2026-98540
- Published
- Oct 18, 2026
- Updated
- Oct 18, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Oct 18, 2026CVE publishedPublication date reported by the CVE source.
- Oct 18, 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=7.1
- Affected versionversion=e0a384434ae1bdfb03954c46c464e3dbd3223ad6 <1d653a183973f5283a3db5a38cd5e195eb152244
- Affected versionversion=e0a384434ae1bdfb03954c46c464e3dbd3223ad6 <b7459fddcb27a4b7d01067678172afa362cf660d
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
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Technologies
Your stack
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Your stack
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