CVE-2026-58081: FreeBSD · Heap-based Buffer Overflow
Affects FreeBSDSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 27 Oct 2026, 14:15 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Aug 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.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| FreeBSD FreeBSD | Affected
| Fixed in– |
AI-suggested
Until a fix is available, avoid processing untrusted input with iconv(3) using the affected encoding modules (HZ, UTF-7, VIQR, ZW).
Description
CVE-2026-58081 is a critical heap-based buffer overflow vulnerability in FreeBSD's iconv encoding modules for HZ, UTF-7, VIQR, and ZW. These modules fail to properly check the size of the output buffer before writing converted characters. Applications using iconv(3) with untrusted input and affected encodings may be vulnerable to buffer overflows, potentially leading to severe impacts on confidentiality, integrity, and availability.