Vulnerabilities

Vulnerability · CVE-2026-98540

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

Published Oct 18, 2026 · catalog updated Oct 18, 2026 · Linux Linux

Open the advisory

Exploitation likelihood is not on this record for CVE-2026-98540. A missing EPSS score is not a low risk. Compare Linux Linux with the linked advisory before you change production.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
  • EPSS is missing. A missing score is not a low risk.
Severity
Unknown—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
Awaiting synchronization with FIRST
Remediation
Not established
Affected products
linux kernel · vendor Linux Linux

In the Linux kernel, the following vulnerability has been resolved: fprobe: Terminate the fgraph_data list when the reservation is not filled fprobe_fgraph_entry() reserves shadow stack space for every fprobe with an exit handler, but only fills it for those whose entry handler returns 0. fgraph_reserve_data() does not clear the area, so fprobe_return() parses the unused tail as headers left over from an earlier call, and an exit handler can run twice or despite its entry handler asking to skip it. Write a zero word after the last entry to terminate the walk. A zeroed slot does not decode to a NULL fprobe on the arches that encode the header into one unsigned long, since arch_decode_fprobe_header_fp() ORs in FPROBE_HEADER_MSB_PATTERN, so make read_fprobe_header() return NULL for a zeroed slot.

Are you affected?

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  • linux kernelversion unspecified
  • vendor Linux Linuxversion unspecified

How to fix CVE-2026-98540

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

Exploitation likelihood is not on this record for CVE-2026-98540. A missing EPSS score is not a low risk. Compare Linux Linux with the linked advisory before you change production.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS is not on this record yet. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 18, 2026 · Linux Kernel CVE

    Detected

    From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: fprobe: Terminate the fgraph_data list when the reservation is not filled fprobe_fgraph_entry() reserves shadow stack space for every fprobe with an exit handler, but only fills it for those whose entry handler returns 0. fgraph_reserve_data() does not clear the area, so fprobe_retu

  2. Oct 18, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: fprobe: Terminate the fgraph_data list when the reservation is not filled fprobe_fgraph_entry() reserves shadow stack space for every fprobe with an exit handler, but only fills it for those whose entry handler returns 0. fgraph_reserve_data() does not clear the area, so fprobe_return() parses the unused tail as headers left over

Sources

  • CVE.orgVulnerability recordCVE-2026-98540

    In the Linux kernel, the following vulnerability has been resolved: fprobe: Terminate the fgraph_data list when the reservation is not filled fprobe_fgraph_entry() reserves shadow stack space for every fprobe with an exit handler, but only fills it for those whose entry handler r

    cve.org
  • Linux Kernel CVEVendor advisoryCVE-2026-98540

    From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: fprobe: Terminate the fgraph_data list when the reservation is not filled fprobe_fgraph_entry() reserves shadow stack space for every fprobe with an exit handler,

    git.kernel.org
  • NIST NVDVulnerability recordCVE-2026-98540

    In the Linux kernel, the following vulnerability has been resolved: fprobe: Terminate the fgraph_data list when the reservation is not filled fprobe_fgraph_entry() reserves shadow stack space for every fprobe with an exit handler, but only fills it for those whose entry handler

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.