CVE-2026-63864: In the Linux kernel, the following vulnerability has been resolved: bpf: Propagate error from visit_tailcall_insn Commit e40f5a6bf88a ("bpf: correct stack liveness for tail calls

highCVSS 8.4CVE-2026-63864

In the Linux kernel, the following vulnerability has been resolved: bpf: Propagate error from visit_tailcall_insn Commit e40f5a6bf88a ("bpf: correct stack liveness for tail calls") added visit_tailcall_insn() but did not check its return value.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: high — CVSS 8.4
Published: 2026-07-19
Last updated: 2026-07-20
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-63864

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-638640.12% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 2% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-63864	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

highUSN-8618-1: Linux kernel vulnerabilitiesubuntu
highUSN-8603-1: Linux kernel (Azure) vulnerabilitiesubuntu
unknownMultiple vulnerabilities in Ubuntu Linux kernel (July 24, 2026)cert-fr-avis
highUSN-8593-1: Linux kernel vulnerabilitiesubuntu

CVE-2026-63864: In the Linux kernel, the following vulnerability has been resolved: bpf: Propagate error from visit_tailcall_insn Commit e40f5a6bf88a ("bpf: correct stack liveness for tail calls

Details

Exploitation outlook

Referenced CVEs

Same CVEs, other sources

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