Verifying-process crash via truncated XMSS signature
Published May 29, 2026 · Updated May 29, 2026
Out-of-bounds reads in liboqs before 0.16.0 allow remote attackers to crash a verifying process with a truncated XMSS or XMSS^MT signature. The XMSS verification path passes the supplied length to xmssmt_core_sign_open, which discards it and lets hash_message read params->sig_bytes from the shorter buffer. Exploitation requires an application built with default-disabled XMSS support enabled to verify an attacker-controlled signature; the read can crash on an unmapped page but cannot disclose adjacent bytes or accept an invalid signature.
Summary
What happened
Out-of-bounds reads in liboqs before 0.16.0 allow remote attackers to crash a verifying process with a truncated XMSS or XMSS^MT signature. The XMSS verification path passes the supplied length to xmssmt_core_sign_open, which discards it and lets hash_message read params->sig_bytes from the shorter buffer. Exploitation requires an application built with default-disabled XMSS support enabled to verify an attacker-controlled signature; the read can crash on an unmapped page but cannot disclose adjacent bytes or accept an invalid signature.
The record
- CVE
- CVE-2026-44518
- Published
- May 29, 2026
- Updated
- May 29, 2026
- Vendor
- Open Quantum Safe
- Product
- liboqs
- Classifications
- CWE-20, CWE-125, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 29, 2026CVE publishedPublication date reported by the CVE source.
- May 29, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.16.0
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
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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