VulnerabilityPublished 25 Sep 2026Updated 21 Oct 2026

CVE-2026-98134: Linux kernel · bpf: check_cond_jmp_op(): properly infer if register is null

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in dfd8f8adda565e08c370c45cf9d6b2511ba9b5c6 : patch Linux kernel soon.

Data as of 26 Oct 2026, 20:21 UTC

Severity

High

Rated High by Threat Radar's AI analysis · 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 dfd8f8adda565e08c370c45cf9d6b2511ba9b5c6, d51cd486930f5bcfd4b55d55ab8e47b03f93d2ed, d3ef6c097ba078e1f8c7239d76a0ce8b61e75095 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Sep 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.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ befae75856ab406a3f3fab2aa2118cf3b2dfe3e6, < dfd8f8adda565e08c370c45cf9d6b2511ba9b5c6	Fixed in dfd8f8adda565e08c370c45cf9d6b2511ba9b5c6
LinuxLinux	Affected ≥ befae75856ab406a3f3fab2aa2118cf3b2dfe3e6, < d51cd486930f5bcfd4b55d55ab8e47b03f93d2ed	Fixed in d51cd486930f5bcfd4b55d55ab8e47b03f93d2ed
LinuxLinux	Affected ≥ befae75856ab406a3f3fab2aa2118cf3b2dfe3e6, < d3ef6c097ba078e1f8c7239d76a0ce8b61e75095	Fixed in d3ef6c097ba078e1f8c7239d76a0ce8b61e75095
LinuxLinux	Affected ≥ befae75856ab406a3f3fab2aa2118cf3b2dfe3e6, < b55c9f019e169ed0d01394f96e172286a8b21b99	Fixed in b55c9f019e169ed0d01394f96e172286a8b21b99
LinuxLinux	Affected ≥ befae75856ab406a3f3fab2aa2118cf3b2dfe3e6, < 9bf96b4347f541604b3caadeabda0773d9ceaf2a	Fixed in 9bf96b4347f541604b3caadeabda0773d9ceaf2a
LinuxLinux	Affected =6.2	Fixed in–

AI-suggested

A fix for this vulnerability has been implemented in the Linux kernel. Users should update to a fixed kernel version containing the patch identified by the provided commit hashes. No additional mitigation steps are indicated by the vendor advisory.

Description

CVE-2026-98134 is a vulnerability in the Linux kernel's BPF verifier where the verifier incorrectly infers that a pointer is non-null. This occurs during pointer comparisons when one pointer type lacks the PTR_MAYBE_NULL flag but can still be null at runtime. The flaw can lead to the verifier missing null pointer dereferences. The issue has been fixed by improving the logic that determines if a register can be null.

Impact

The vulnerability allows the BPF verifier to incorrectly assume that certain pointers are non-null, which can lead to missed detection of null pointer dereferences. This could result in unsafe memory access during BPF program execution, potentially causing kernel instability or crashes. However, no public exploits or in-the-wild attacks are known at this time.

Summary

This vulnerability in the Linux kernel's BPF verifier arises from improper inference of pointer nullability in the check_cond_jmp_op() function. Specifically, when comparing two pointers, the verifier assumes a pointer without the PTR_MAYBE_NULL flag cannot be null, which is incorrect for certain pointer types like PTR_TO_MEM. This can cause the verifier to miss null pointer dereferences, potentially leading to unsafe memory operations. The fix replaces the type_may_be_null() check with reg_not_null(), which uses an allowlist of pointer types for which absence of PTR_MAYBE_NULL truly means non-null. The patch extends reg_not_null() to cover additional pointer types and removes special cases, improving the accuracy of null pointer inference in the verifier.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 20:21 UTC

Technical details

References

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