PatchTheCVECVE-2026-34610: The leancrypto library is a cryptographic library that exclusively contains only PQC-resistant cryptographic a
CVE-2026-34610 is a medium-severity flaw (CVSS 5.9) affecting leancrypto. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 vic
Why this priority
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.9 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.2% (top 95%) |
| CISA exploited list | No |
| Weakness | CWE-681 |
| Published | 2026-04-02 |
| Last modified | 2026-07-24 |
Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-34610?
leancrypto: upgrade to 1.7.1. Exact commands for each OS are on this page.
Is CVE-2026-34610 being exploited?
CVE-2026-34610 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-34610 affect?
CVE-2026-34610 affects leancrypto. Severity is medium (CVSS 5.9). 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) l
How urgent is CVE-2026-34610?
Priority 27/100. Remotely exploitable, no login, no user action