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NVD / CVE Program· CNA GitHub_M

CVE-2026-46344: liboqs: Heap-buffer-overflow in XMSS verification path via OID-controlled parameter mismatch (xmss_commons.c:194)

MediumCVSS 5.3 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 21/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.30% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: open-quantum-safe liboqs 0.16.0.

Low priority for now. Upgrade to open-quantum-safe liboqs 0.16.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

liboqs is a C-language cryptographic library that provides implementations of post-quantum cryptography algorithms. Prior to 0.16.0, an out-of-bounds read has been identified in the XMSS and XMSS^MT stateful signature verification code. When the verification function is called with a correctly-sized signature buffer for the declared algorithm but a public key whose OID bytes (pk[0..3]) reference a different XMSS parameter set with a larger sig_bytes, the implementation re-parses the OID from the public key inside xmss_sign_open / xmssmt_sign_open and uses the resulting (larger) sig_bytes to index the caller-supplied signature buffer. As with CVE-2026-44518, the out-of-bounds bytes are consumed only as input to an internal hash computation and are not returned to the caller, so no oracle exists to leak their contents to an attacker. The primary observable effect is a possible crash (denial of service) of the verifying process if the read crosses into an unmapped memory page. This vulnerability is fixed in 0.16.0.

Published
May 29, 2026
Updated
Jul 22, 2026
EPSS
0.3% · 23th percentile

Report tools

JSON

Action score

21

Monitor

Low priority for now.

CVSS
21 / 40 · 5.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
5.3
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-46344

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
openquantumsafeliboqs

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • open-quantum-safe liboqs

    • < 0.16.0affected

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • openquantumsafe liboqsup to 0.15.0 inclusive

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
openSUSE:Leap 16.0liboqsbefore 0.16.0-160000.1.10.16.0-160000.1.1
openSUSE:Leap 16.0oqs-providerbefore 0.11.0.32-160000.1.10.11.0.32-160000.1.1
openSUSE:Tumbleweedliboqsbefore 0.16.0-2.10.16.0-2.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7liboqsbefore 0.16.0-150600.3.6.10.16.0-150600.3.6.1
SUSE:Linux Enterprise Module for Basesystem 15 SP7oqs-providerbefore 0.11.0.32-150600.3.9.10.11.0.32-150600.3.9.1
SUSE:Linux Enterprise Server 16.0liboqsbefore 0.16.0-160000.1.10.16.0-160000.1.1
SUSE:Linux Enterprise Server 16.0oqs-providerbefore 0.11.0.32-160000.1.10.11.0.32-160000.1.1

Other highest-scoring records for the same primary product.

  • CVE-2024-31510An issue in Open Quantum Safe liboqs v.10.0 allows a remote attacker to escalate privileges via the crypto_sign_signature parameter in the…
    39Monitor
  • CVE-2024-54137liboqs has a correctness error in HQC decapsulation
    30Monitor
  • CVE-2024-36405Control-flow timing leak in Kyber reference implementation when compiled with Clang 15-18 for -Os, -O1 and other options
    30Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2025-48946May 30, 2025 · liboqs affected by theoretical design flaw in HQC
    14Monitor
  • ← EarlierCVE-2025-52473Jul 10, 2025 · liboqs secret-dependent branching in HQC reference implementation when compiled with Clang 17-20
    22Monitor
  • ← EarlierCVE-2026-44518May 29, 2026 · liboqs: XMSS Buffer Overread Bug
    21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
open-quantum-safe liboqs0.16.0 · descriptionVendor (CNA)
opensuse:liboqs0.16.0-2.1 · openSUSE:TumbleweedPackage registry (OSV)
opensuse:oqs-provider0.11.0.32-160000.1.1 · openSUSE:Leap 16.0Package registry (OSV)
suse:liboqs0.16.0-160000.1.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)
suse:oqs-provider0.11.0.32-160000.1.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
low · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
Low

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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