CVE-2026-63864
HIGH
Published Jul 19, 2026
Modified Jul 20, 2026
Description
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.
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CVSS v3.1 Score
8.4
HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS — Exploit Prediction
0.0012
Probability of exploitation
0.02%
Percentile rank
EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.
References
Frequently Asked Questions
What is 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") added
visit_tailcall_insn() but did not check its return value. It has a CVSS v3.1 base score of 8.4 (HIGH).
How severe is CVE-2026-63864? +
CVE-2026-63864 has a CVSS v3.1 score of 8.4 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0012, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-63864? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.
