CVE-2026-26007

Description

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 46.0.5, the public_key_from_numbers (or EllipticCurvePublicNumbers.public_key()), EllipticCurvePublicNumbers.public_key(), load_der_public_key() and load_pem_public_key() functions do not verify that the point belongs to the expected prime-order subgroup of the curve. This missing validation allows an attacker to provide a public key point P from a small-order subgroup. This can lead to security issues in various situations, such as the most commonly used signature verification (ECDSA) and shared key negotiation (ECDH). When the victim computes the shared secret as S = [victim_private_key]P via ECDH, this leaks information about victim_private_key mod (small_subgroup_order). For curves with cofactor > 1, this reveals the least significant bits of the private key. When these weak public keys are used in ECDSA , it's easy to forge signatures on the small subgroup. Only SECT curves are impacted by this. This vulnerability is fixed in 46.0.5.

References

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26007.json

https://github.com/pyca/cryptography/security/advisories/GHSA-r6ph-v2qm-q3c2

https://github.com/pyca/cryptography/commit/0eebb9dbb6343d9bc1d91e5a2482ed4e054a6d8c

https://bugzilla.redhat.com/show_bug.cgi?id=2438762

https://access.redhat.com/security/cve/CVE-2026-26007

https://access.redhat.com/errata/RHSA-2026:7295

https://access.redhat.com/errata/RHSA-2026:6568

https://access.redhat.com/errata/RHSA-2026:6567

https://access.redhat.com/errata/RHSA-2026:6497

https://access.redhat.com/errata/RHSA-2026:6309

https://access.redhat.com/errata/RHSA-2026:6308

https://access.redhat.com/errata/RHSA-2026:5665

https://access.redhat.com/errata/RHSA-2026:5168

https://access.redhat.com/errata/RHSA-2026:2694

https://access.redhat.com/errata/RHSA-2026:22993

https://access.redhat.com/errata/RHSA-2026:22330

https://access.redhat.com/errata/RHSA-2026:21517

https://access.redhat.com/errata/RHSA-2026:21431

https://access.redhat.com/errata/RHSA-2026:19355

https://access.redhat.com/errata/RHSA-2026:13672

https://access.redhat.com/errata/RHSA-2026:13553

https://access.redhat.com/errata/RHSA-2026:13545

https://access.redhat.com/errata/RHSA-2026:13512

https://access.redhat.com/errata/RHSA-2026:12176

https://access.redhat.com/errata/RHSA-2026:10184

http://www.openwall.com/lists/oss-security/2026/02/10/4

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4

EPSS