Libarchive: libarchive: signed integer overflow in archive_write_zip_header (CVE-2026-16517) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-16517

Libarchive: libarchive: signed integer overflow in archive_write_zip_header

Answer in brief

CVE-2026-16517 records a Unknown severity vulnerability in Libarchive: libarchive: signed integer overflow in archive_write_zip_header. The current sources do not mark it as known exploited. Affected software not mapped in the current feed; confirm the named product and version against your inventory.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 21, 2026Updated Aug 19, 2026Source checked Aug 19, 2026First seen by HOL Aug 19, 2026Material review Aug 19, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: Not mapped
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

Affected software not mapped in the current feed; confirm the named product and version against your inventory.

Recommended response

Confirm exposure. Identify whether the named product or interface exists in your inventory, then review the linked upstream references for affected versions and vendor guidance.

Evidence timeline and material changes

Published upstream
Jul 21, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 19, 2026

Sources and claim methodology

Upstream source description

A signed integer overflow vulnerability was found in libarchive's ZIP writer. In the archive_write_zip_header function in archive_write_set_format_zip.c, when ZIP encryption is enabled and the entry file size is close to INT64_MAX, the addition of the encryption overhead to the entry size overflows int64_t, resulting in undefined behavior. This could lead to incorrect Zip64 extension decisions or potential memory corruption.

Quoted source text, attributed separately from HOL analysis.