What is CVE-2026-88840?

CVE-2026-88840 is a medium-severity vulnerability in Red Hat Hardened Images, classified under Out-of-bounds Read. CVSS score: 5.3/10. Published 2026-09-23.

How severe is CVE-2026-88840?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Out-of-bounds Read in Red Hat Hardened Images

CVE-2026-88840

BusyBox TLS get_client_hello() reads past the end of the input buffer when parsing a truncated ClientHello message.

Vulnerability class: Buffer Overflow

Published 2026-09-23 · last modified 2026-09-26.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (10.6th percentile), scored 2026-11-04.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 10.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Red Hat Hardened Images

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

access.redhat.com/security/cve/CVE-2026-88840 (vdb-entry)
bugzilla.redhat.com/show_bug.cgi (issue-tracking)

Frequently asked questions

What is CVE-2026-88840?: CVE-2026-88840 is a medium-severity vulnerability in Red Hat Hardened Images, classified under Out-of-bounds Read. CVSS score: 5.3/10. Published 2026-09-23.
How severe is CVE-2026-88840?: Medium severity. CVSS v3 base score is 5.3 out of 10.