VulnerabilityPublished 18 Oct 2026

CVE-2026-98799: Linux kernel · bpf: Skip detached progs in trampoline images that are still in use

Source GCVE Database

Authoritative record:CVE-2026-98799· High

Not known to be exploited · fixed in 967566ad325b42150483e81acb09ea9d800c00b8 : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 967566ad325b42150483e81acb09ea9d800c00b8, 17637e1a581a22466ac3620a91e099683ff9cc6f, 5.12 +1

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-h23c-62pq-37fc

What to do

Upgrade Linux kernel to 967566ad325b42150483e81acb09ea9d800c00b8, 17637e1a581a22466ac3620a91e099683ff9cc6f, 5.12 or 5.11.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected >=5.10.28 <5.11 >=5.11.11 <5.12	Fixed in 967566ad325b42150483e81acb09ea9d800c00b8 17637e1a581a22466ac3620a91e099683ff9cc6f 5.12 5.11
LinuxLinux	Affected =5.12	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to address this vulnerability by patching no-op instructions to jumps when BPF programs are detached, preventing premature freeing of programs still in use. Users should update to the fixed Linux kernel versions containing this patch. No additional mitigations are indicated.

Description

A vulnerability in the Linux kernel's BPF trampoline handling was resolved. The issue involved detached BPF programs being freed while tasks might still be running in them, potentially causing kernel crashes. The fix ensures that detached programs are not freed prematurely by patching no-op instructions to jumps, preserving program execution safety. This addresses a race condition where tasks sleeping in certain BPF programs could resume execution in freed memory, leading to kernel Oops errors.

Impact

The vulnerability could lead to kernel crashes (Oops) due to tasks resuming execution in freed BPF program memory after detachment. This affects system stability and could cause denial of service. There is no indication of code execution or privilege escalation from the provided data.

Summary

The vulnerability in the Linux kernel's BPF trampoline mechanism stemmed from improper handling of detached BPF programs within trampoline images. While the trampoline image itself was protected from being freed while in use, the individual BPF programs called by the image were not similarly protected. When a program was detached, its last reference was dropped immediately, and it was freed after grace periods without accounting for tasks sleeping in other BPF programs that called the detached program. This could cause tasks to resume execution in freed program memory, resulting in kernel crashes (e.g., int3 traps). The fix involves having JIT compilers emit patchable no-op instructions before each program call, which are patched to jumps when a program is detached, ensuring that tasks running in any trampoline image are not exposed to freed program memory. This also required lowering the maximum number of trampoline links on some architectures due to increased instruction size.

References

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