CVE-2026-16517: Libarchive: libarchive: signed integer overflow in archive_write_zip_header

lowCVSS 2.9CVE-2026-16517

CSIRTS triage

vendor: Libarchive product: libarchiveOther

What: A signed integer overflow vulnerability exists in the archive_write_zip_header function.
Who is affected: Deployments using libarchive are affected.
Urgency: Remediation urgency is low due to low severity (CVSS 2.9) and no known exploitation.
Action: Consider updating to a patched version when available.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: low — CVSS 2.9
Published: 2026-07-14
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-16517

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-165170.08% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 0% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-16517	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for Libarchive

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

low[NEW] [low] libarchive: Vulnerability allows unspecified attackcert-bund · 2026-07-23
medium[UPDATE] [medium] libarchive: Vulnerability allows denial of servicecert-bund · 2026-07-22
low[NEW] [low] libarchive: Vulnerability allows code execution and DoScert-bund · 2026-07-22
lowCVE-2026-16517: A signed integer overflow vulnerability was found in libarchive's ZIP writer. In the archive_w…nvd · 2026-07-21
unknownUSN-8581-1: libarchive vulnerabilitiesubuntu · 2026-07-21
lowCVE-2026-15028: Libarchive: heap overflow oob read while parsing a tar archive contains a pax extended headermsrc · 2026-07-14