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

Status: published. Published: 2026-07-21. Updated: 2026-11-02.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 10 (libarchive): ≥ 0:3.7.7-11.el10_2; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Hardened Images (libarchive-main): ≥ 3.8.8-3.1.hum1; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (libarchive): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (libarchive): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (libarchive): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (libarchive): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 5 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 2.9 (low); CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.10% as of 2026-11-02; percentile 1.04%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-190

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2026:43818 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:69553 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-16517 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2505492 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-16517; retrieved 2026-11-02; source updated 2026-11-02

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-16517; retrieved 2026-11-02; source updated Not reported

Revision: 3789f6e02b561baa49f21a6e82dc416acbf54bab772762ee7b35583e921df5e2

Canonical: https://y2.dev/cve/CVE-2026-16517

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