VulnerabilityPublished 18 Oct 2026

CVE-2026-98540: Linux kernel · fprobe: Terminate the fgraph_data list when the reservation is not filled

Source GCVE Database

Authoritative record:CVE-2026-98540· Medium

Not known to be exploited : upgrade to b7459fddcb27a4b7d01067678172afa362cf660d or 1d653a183973f5283a3db5a38cd5e195eb152244 when convenient.

Data as of 26 Oct 2026, 17:16 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in b7459fddcb27a4b7d01067678172afa362cf660d, 1d653a183973f5283a3db5a38cd5e195eb152244

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-9jj3-9f6g-g6xw

What to do

Upgrade Linux kernel to b7459fddcb27a4b7d01067678172afa362cf660d or 1d653a183973f5283a3db5a38cd5e195eb152244.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ e0a384434ae1bdfb03954c46c464e3dbd3223ad6, < b7459fddcb27a4b7d01067678172afa362cf660d	Fixed in b7459fddcb27a4b7d01067678172afa362cf660d
LinuxLinux	Affected ≥ e0a384434ae1bdfb03954c46c464e3dbd3223ad6, < 1d653a183973f5283a3db5a38cd5e195eb152244	Fixed in 1d653a183973f5283a3db5a38cd5e195eb152244
LinuxLinux	Affected =7.1	Fixed in–

AI-suggested

A fix has been implemented that writes a zero word after the last valid fgraph_data entry to terminate the list properly. Users should apply the official Linux kernel update that includes this fix once available. Patch status is not explicitly confirmed in the provided data; check the vendor advisory for current remediation guidance.

Description

A vulnerability in the Linux kernel's fprobe component was resolved involving improper termination of the fgraph_data list when a reservation is not filled. The issue caused fprobe_return() to misinterpret unused shadow stack space as valid headers, potentially causing an exit handler to run twice or run despite being skipped. The fix involves writing a zero word after the last entry to properly terminate the list and prevent incorrect parsing.

References

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