VulnerabilityPublished 18 Oct 2026

CVE-2026-98800: Linux kernel · bpf: Wait for an RCU tasks grace period before freeing trampoline progs

Source GCVE Database

Authoritative record:CVE-2026-98800· High

Not known to be exploited · fixed in 40955f6512a03f0e046f5256b0706b26ba191018 : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 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 40955f6512a03f0e046f5256b0706b26ba191018, 5.12, 5.11 +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-hw45-3jc9-w8mr

What to do

Upgrade Linux to 40955f6512a03f0e046f5256b0706b26ba191018, 5.12, 5.11 or 0fb5751a6e411b1b466c06e50021818d9391df98; the Red Hat redhat/kernel package to 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 40955f6512a03f0e046f5256b0706b26ba191018 5.12 5.11 0fb5751a6e411b1b466c06e50021818d9391df98
LinuxLinux	Affected =5.12	Fixed in–
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected >=5.10.28 <5.11 >=5.11.11 <5.12 =5.12	Fixed in 5.11 5.12

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 wait for an RCU tasks grace period before freeing trampoline-linked BPF programs, preventing use-after-free conditions. Users should update to the fixed kernel version once available. No additional mitigation steps are indicated.

Description

A use-after-free vulnerability in the Linux kernel's BPF trampoline program handling was resolved by ensuring an RCU tasks grace period is waited for before freeing trampoline programs. This addresses a race condition on preemptible kernels where a task preempted in the trampoline could call a freed program, causing a kernel memory access error.

References

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