VulnerabilityReceived

CVE-2026-45271

Picotls is a TLS protocol library that allows users select different crypto backends based on their use case.

MEDIUM 5.5EPSS 0.11%

Does this matter?

Lower severity and a low EPSS score (0.11%). Track it; it rarely justifies an emergency change on its own.

Description

Picotls is a TLS protocol library that allows users select different crypto backends based on their use case. Picotls implements its own ASN.1 validation helper, which is used by the minicrypto backend while parsing local PKCS#8 private keys. Prior to commit c14231d801407640bc42c2dcf92783409ea6a7c7, the validator recursively descends into constructed ASN.1 elements without enforcing a maximum nesting depth. If an application loads an attacker-supplied private-key file through ptls_minicrypto_load_private_key(), or otherwise calls the public ASN.1 validation API on untrusted DER, a crafted deeply nested ASN.1 structure can exhaust the process stack and crash the application. Note that the libcrypto (OpenSSL) backend does not use the ASN.1 validation helper of picotls, and therefore is immune to this vulnerability. The vulnerability has been addressed in commit c14231d801407640bc42c2dcf92783409ea6a7c7.

CVSS 3.1: 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS: 0.11% probability · 2th percentile
CISA KEV: Not listed
Weakness: CWE-835
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.