VulnerabilityPublished 6 Nov 2026

CVE-2026-104254: open-quantum-safe liboqs · Out-of-bounds Read

Affects open-quantum-safe liboqsSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium · fixed in 0.17.0 : update open-quantum-safe liboqs when convenient.

Data as of 6 Nov 2026, 21:34 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	5.3

Patch: Available – fixed in 0.17.0

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
open-quantum-safeliboqs	Affected >=0.11.0 <=0.16.0	Fixed in–

AI-suggested

Users should upgrade to liboqs version 0.17.0 or later once it is released to address this vulnerability. Until then, be aware that builds configured with OQS_ENABLE_SIG_STFL_LMS=ON in versions 0.11.0 through 0.16.0 are affected. No other mitigations are specified.

Description

A medium-severity out-of-bounds read vulnerability exists in the open-quantum-safe liboqs library versions 0.11.0 through 0.16.0 when built with OQS_ENABLE_SIG_STFL_LMS=ON. The flaw allows reading up to 32 bytes beyond a caller-supplied signature buffer during verification of truncated LMS or HSS-LMS signatures, and up to 8 bytes in public key validation. The read data is only used internally for hashing and is not exposed externally. This can cause a verifier crash and denial of service but does not lead to memory disclosure or acceptance of invalid signatures. The issue is scheduled to be fixed in version 0.17.0.

Impact

The vulnerability can cause a denial of service via verifier crashes due to out-of-bounds reads of up to 32 bytes past the signature buffer or 8 bytes past the public key buffer. There is no impact on confidentiality or integrity since the read data is not exposed externally and invalid signatures are not accepted.

Summary

liboqs, a C cryptographic library implementing post-quantum algorithms, has an out-of-bounds read vulnerability (CWE-125) in versions 0.11.0 through 0.16.0 when configured with OQS_ENABLE_SIG_STFL_LMS=ON. The vulnerability occurs in the functions OQS_SIG_STFL_verify and OQS_SIG_STFL_alg_lms_verify due to insufficient consumed-length checks in hss_validate_signature_init(), allowing up to 32 bytes to be read beyond the signature buffer. Additionally, in version 0.16.0, is_hss_public_key() reads beyond a four-byte length check, allowing an 8-byte over-read. No valid signature is required, but the public key must be syntactically plausible. The out-of-bounds data is only used internally for hashing, so the impact is limited to potential crashes and denial of service, without memory disclosure or signature forgery. A fix is planned for version 0.17.0.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 21:34 UTC

WeaknessesCWE-125

Technical details

References

Community reviews

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