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CVE-2026-26007VulnerabilityPublished Updated

Python cryptography: Prior to 46.0.5, the public_key_from_numbers (or EllipticCurvePublicNumbers.public_key())

Affects python-cryptographySource GCVE Database

0
Authoritative record:CVE-2026-26007· High 8.2

Not known to be exploited · CVSS 8.2 High · fixed in 1.2.3-1ubuntu0.3+esm3 : patch python-cryptography soon.

Data as of 27 Oct 2026, 06:42 UTC

CVSS 4.0 base score
8.2High
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 1.2.3-1ubuntu0.3+esm3, 2.1.4-1ubuntu1.4+esm3, 2.8-3ubuntu0.3+esm2 +3
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 10 Feb 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 25.10python-cryptographypkg:deb/ubuntu/python-cryptography?arch=source&distro=questingOther threatsAffected
  • <43.0.0-1ubuntu1.1
Fixed in
  • 43.0.0-1ubuntu1.1
Ubuntu 24.04 LTSpython-cryptographypkg:deb/ubuntu/python-cryptography?arch=source&distro=nobleOther threatsAffected
  • <41.0.7-4ubuntu0.3
Fixed in
  • 41.0.7-4ubuntu0.3
Ubuntu 22.04 LTSpython-cryptographypkg:deb/ubuntu/python-cryptography?arch=source&distro=jammyOther threatsAffected
  • <3.4.8-1ubuntu2.3
Fixed in
  • 3.4.8-1ubuntu2.3
Ubuntu Pro 20.04 LTSpython-cryptographypkg:deb/ubuntu/python-cryptography?arch=source&distro=esm-infra/focalOther threatsAffected
  • <2.8-3ubuntu0.3+esm2
Fixed in
  • 2.8-3ubuntu0.3+esm2
Ubuntu Pro 18.04 LTSpython-cryptographypkg:deb/ubuntu/python-cryptography?arch=source&distro=esm-infra/bionicOther threatsAffected
  • <2.1.4-1ubuntu1.4+esm3
Fixed in
  • 2.1.4-1ubuntu1.4+esm3
Ubuntu Pro 16.04 LTSpython-cryptographypkg:deb/ubuntu/python-cryptography?arch=source&distro=esm-infra/xenialOther threatsAffected
  • <1.2.3-1ubuntu0.3+esm3
Fixed in
  • 1.2.3-1ubuntu0.3+esm3

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

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

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