VulnerabilityPublished 18 Oct 2026

CVE-2026-98816: Linux kernel · bpf: Fix overflow of jump offset in constant blinding

Source GCVE Database

Authoritative record:CVE-2026-98816· Medium

Not known to be exploited : upgrade to ad139384ecddb6f3e7e3c3c12765aafae0e39670 or 443328237113ee0ea515e506497334d871dbc2aa 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 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in ad139384ecddb6f3e7e3c3c12765aafae0e39670, 443328237113ee0ea515e506497334d871dbc2aa

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-6x96-v5fq-fjjw

What to do

Upgrade Linux kernel to ad139384ecddb6f3e7e3c3c12765aafae0e39670 or 443328237113ee0ea515e506497334d871dbc2aa.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 4f3446bb809f20ad56cadf712e6006815ae7a8f9, < ad139384ecddb6f3e7e3c3c12765aafae0e39670	Fixed in ad139384ecddb6f3e7e3c3c12765aafae0e39670
LinuxLinux	Affected ≥ 4f3446bb809f20ad56cadf712e6006815ae7a8f9, < 443328237113ee0ea515e506497334d871dbc2aa	Fixed in 443328237113ee0ea515e506497334d871dbc2aa
LinuxLinux	Affected =4.7	Fixed in–
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected =4.7	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix has been implemented in the Linux kernel to return an error (-ERANGE) when the jump offset overflow condition is detected, preventing the kernel crash. Users should update to the fixed kernel version once available. No additional mitigation steps are indicated.

Description

A vulnerability in the Linux kernel's BPF JIT compiler was fixed to address an overflow of the jump offset in the constant blinding function bpf_jit_blind_insn(). This overflow could cause backward jumps to wrap around and become large forward jumps, potentially crashing the kernel when running certain BPF programs with bpf_jit_harden=2 enabled.

Impact

The vulnerability can cause the Linux kernel to crash (kernel panic) when executing specially crafted BPF programs with the bpf_jit_harden=2 setting enabled. This results in a denial of service condition. There is no indication of code execution or privilege escalation from the provided data.

Summary

The vulnerability involves the bpf_jit_blind_insn() function in the Linux kernel, which rewrites conditional jump instructions by blinding constants. When the jump offset (off) is negative and near the lower bound of a signed 16-bit integer (s16), subtracting 2 causes an integer overflow, wrapping the jump offset to a large positive value. This results in the jump going beyond the end of the BPF program. The kernel's branch adjustment function bpf_adj_branches() does not check this overflow because the jump is modified inside the patch. Consequently, running such a BPF program with bpf_jit_harden=2 causes a kernel crash. The fix returns an -ERANGE error when such an overflow would occur, preventing the crash. The related function bpf_jit_blind_constants() has a similar issue when blinding other instructions that move jumps out of range.

References

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