How severe is CVE-2026-34610?

CVE-2026-34610 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-34610 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34610?

CVE-2026-34610 affects Leancrypto. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-34610?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-34610 have an EU (EUVD) identifier?

Yes. CVE-2026-34610 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18466.

When was CVE-2026-34610 published?

CVE-2026-34610 was published on 2026-04-02 and last updated on 2026-06-17.

CVE-2026-34610

CVE-2026-34610 is a medium-severity vulnerability in Leancrypto with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-681.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
EPSS exploit prediction: 0% (6th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18466
Weakness: CWE-681
Affected product: Leancrypto
Published: 2026-04-02
Last modified: 2026-06-17

Description

The leancrypto library is a cryptographic library that exclusively contains only PQC-resistant cryptographic algorithms. Prior to version 1.7.1, lc_x509_extract_name_segment() casts size_t vlen to uint8_t when storing the Common Name (CN) length. An attacker who crafts a certificate with CN = victim's CN + 256 bytes padding gets cn_size = (uint8_t)(256 + N) = N, where N is the victim's CN length. The first N bytes of the attacker's CN are the victim's identity. After parsing, the attacker's certificate has an identical CN to the victim's — enabling identity impersonation in PKCS#7 verification, certificate chain matching, and code signing. This issue has been patched in version 1.7.1.

Frequently asked questions

What is CVE-2026-34610?: The leancrypto library is a cryptographic library that exclusively contains only PQC-resistant cryptographic algorithms. Prior to version 1.7.1, lc_x509_extract_name_segment() casts size_t vlen to uint8_t when storing the Common Name (CN) length. An attacker who crafts a certificate with CN = victim's CN + 256 bytes padding gets cn_size = (uint8_t)(256 + N) = N, where N is the victim's CN length. The first N bytes of the attacker's CN are the victim's identity. After parsing, the attacker's certificate has an identical CN to the victim's — enabling identity impersonation in PKCS#7 verification, certificate chain matching, and code signing. This issue has been patched in version 1.7.1.
How severe is CVE-2026-34610?: CVE-2026-34610 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-34610 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34610?: CVE-2026-34610 affects Leancrypto. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-34610?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-34610 have an EU (EUVD) identifier?: Yes. CVE-2026-34610 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18466.
When was CVE-2026-34610 published?: CVE-2026-34610 was published on 2026-04-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:leancrypto:leancrypto:*:*:*:*:*:*:*:*

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