Undefined behavior via encrypted ZIP size overflow
Published Jul 21, 2026 · Updated Jul 21, 2026
Signed integer overflow in libarchive within Red Hat Hardened Images allows local users to trigger undefined behavior through encrypted ZIP output. The archive_write_zip_header function adds encryption overhead to a caller-supplied size near INT64_MAX before deciding on Zip64, overflowing int64_t. Reachability requires an application to enable ZIP encryption and submit an extreme declared entry size; sanitizer-instrumented processes abort, while other builds can make incorrect Zip64 decisions or corrupt memory.
Summary
What happened
Signed integer overflow in libarchive within Red Hat Hardened Images allows local users to trigger undefined behavior through encrypted ZIP output. The archive_write_zip_header function adds encryption overhead to a caller-supplied size near INT64_MAX before deciding on Zip64, overflowing int64_t. Reachability requires an application to enable ZIP encryption and submit an extreme declared entry size; sanitizer-instrumented processes abort, while other builds can make incorrect Zip64 decisions or corrupt memory.
The record
- CVE
- CVE-2026-16517
- Published
- Jul 21, 2026
- Updated
- Jul 21, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Hardened Images
- Classifications
- CWE-190
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 21, 2026CVE publishedPublication date reported by the CVE source.
- Jul 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Encrypted ZIP size-overflow proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo