CVE-2026-26007
ADVISORY - githubSummary
Vulnerability Summary
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.
Credit
This vulnerability was discovered by:
- XlabAI Team of Tencent Xuanwu Lab
- Atuin Automated Vulnerability Discovery Engine
Common Weakness Enumeration (CWE)
Insufficient Verification of Data Authenticity
Insufficient Verification of Data Authenticity
Improper Validation of Integrity Check Value
GitHub
-
CVSS SCORE
8.2high| Package | Type | OS Name | OS Version | Affected Ranges | Fix Versions |
|---|---|---|---|---|---|
| cryptography | pypi | - | - | <=46.0.4 | 46.0.5 |
CVSS:4 Severity and metrics
The CVSS metrics represent different qualitative aspects of a vulnerability that impact the overall score, as defined by the CVSS Specification.
The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone). One example of an Adjacent attack would be an ARP (IPv4) or neighbor discovery (IPv6) flood leading to a denial of service on the local LAN segment (e.g., CVE-2013-6014).
A successful attack depends on conditions beyond the attacker's control, requiring investing a measurable amount of effort in research, preparation, or execution against the vulnerable component before a successful attack.
The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
The vulnerable system can be exploited without interaction from any human user, other than the attacker. Examples include: a remote attacker is able to send packets to a target system a locally authenticated attacker executes code to elevate privileges.
There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
There is no loss of integrity within the Vulnerable System.
There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
There is no impact to availability within the Vulnerable System.
There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
NIST
2.8
CVSS SCORE
8.2highAlpine
-
Debian
-
Ubuntu
2.8
CVSS SCORE
6.5mediumRed Hat
2.2
CVSS SCORE
7.4highChainguard
CGA-m9f5-5299-w337
-
minimos
MINI-2fm3-c6mh-c9pj
-
minimos
MINI-3ff3-q6fq-62rg
-
minimos
MINI-5vgr-73mq-r7cw
-
minimos
MINI-fgc2-6fc4-rfxp
-
minimos
MINI-gp6v-h33c-xjp3
-
minimos
MINI-pjqr-767r-775w
-
minimos
MINI-v735-28mp-3x5q
-