CVE-2026-58081

Heap based buffer overflow in iconv(3)

Published Aug 19, 2026 CVSS 3.1 · 9.8 Critical EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:o:freebsd:freebsd:14.3:-:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p10:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p11:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p12:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p13:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p14:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p15:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p3:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p4:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p5:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p6:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p7:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p8:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.3:p9:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:-:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:p1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:p2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:p3:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:p4:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:p5:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:p6:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:14.4:rc1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:-:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p10:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p1:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p3:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p4:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p5:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p6:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p7:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p8:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.0:p9:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.1:-:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.1:rc2:*:*:*:*:*:*
cpe:2.3:o:freebsd:freebsd:15.1:rc3-p1:*:*:*:*:*:*
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Weaknesses CWE-120
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H'}

threat_severity

Important

Type Values Removed Values Added
First Time appeared Freebsd
Freebsd freebsd
Vendors & Products Freebsd
Freebsd freebsd
Type Values Removed Values Added
Description 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.
Title Heap based buffer overflow in iconv(3)
Weaknesses CWE-122
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
freebsd
Published
Updated
Aug 26, 2026, 5:56 PM
Reserved
Jun 29, 2026, 1:40 AM
Status
Analyzed
Published
Aug 19, 2026, 8:17 AM
Modified
Oct 27, 2026, 12:10 PM
Severity
Important
Public date
Aug 19, 2026, 7:20 AM