VulnerabilityPublished 25 Sep 2026Updated 21 Oct 2026

CVE-2026-98043: Linux kernel · bpf: Don't infer non-NULL from a pointer with an unbounded offset

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in cb6642048739bf4ee5aa09fe465511f1e87caa63 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in cb6642048739bf4ee5aa09fe465511f1e87caa63, 67b529f521a6676cdfc78b91b0217d7eaa84216b, 65bea674f43c09c0eda033a140dfac6a2842a19f +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 ≥ cac616db39c207dc63465a4e05c6ce0e60b2cce4, < cb6642048739bf4ee5aa09fe465511f1e87caa63	Fixed in cb6642048739bf4ee5aa09fe465511f1e87caa63
LinuxLinux	Affected ≥ cac616db39c207dc63465a4e05c6ce0e60b2cce4, < 67b529f521a6676cdfc78b91b0217d7eaa84216b	Fixed in 67b529f521a6676cdfc78b91b0217d7eaa84216b
LinuxLinux	Affected ≥ cac616db39c207dc63465a4e05c6ce0e60b2cce4, < 65bea674f43c09c0eda033a140dfac6a2842a19f	Fixed in 65bea674f43c09c0eda033a140dfac6a2842a19f
LinuxLinux	Affected ≥ cac616db39c207dc63465a4e05c6ce0e60b2cce4, < 019d845a08b8ccfe8eefaaf4bca6870f2b8c58ae	Fixed in 019d845a08b8ccfe8eefaaf4bca6870f2b8c58ae
LinuxLinux	Affected ≥ cac616db39c207dc63465a4e05c6ce0e60b2cce4, < 8b414dbe97fcefd116e5a620c3bd9993014aa4ce	Fixed in 8b414dbe97fcefd116e5a620c3bd9993014aa4ce
LinuxLinux	Affected =5.8	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Don't infer non-NULL from a pointer with an unbounded offset reg_not_null() decides that a register holds a non-NULL value by looking at its type alone. For pointer types that allow arithmetic the type only guarantees a non-NULL base, in case of an unbound offset the runtime offset value might still add up to NULL. Consider the followng program: r6 = bpf_map_lookup_elem(map, &0); /* present */ if (r6 == 0) return 0; r7 = bpf_map_lookup_elem(map, &1); /* absent, NULL at runtime */ r8 = r7; r8 -= r6; /* pointer - pointer: unknown scalar, -r6 */ r8 <<= 1; r8 >>= 1; /* any non-negative offset is accepted by */ /* check_reg_sane_offset_ptr() */ r6 += r8; /* verifier: map value; runtime: zero */ if (r7 != r6) return 0; *(u8 *)(r7 + 0); /* r7 is inferred non-NULL, both are zero */ At runtime both registers are zero, the comparison is true and the load faults with NULL pointer dereference. Require the offset to be within +-BPF_MAX_VAR_OFF in reg_not_null().

References

Community reviews

Loading reviews…