Buffer overflow in FreeBSD

CVE-2026-58081

Several encoding modules, including HZ, UTF-7, VIQR, and ZW, did not properly check the size of the caller-supplied output buffer before writing converted characters. An application that uses iconv(3) to convert untrusted input to or from one of the affected encodings may be vulnerable to buffer overflows if it uses one of the affected encoding modules.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (42.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-58081: held from 0.004 to 0.005.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.002

Affected products

  • FreeBSD — versions 14.3, 15.0, 14.4

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-58081?
CVE-2026-58081 is a critical-severity vulnerability in FreeBSD, classified under Heap-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-08-19.
How severe is CVE-2026-58081?
Critical severity. CVSS v3 base score is 9.8 out of 10.