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CVE Record

CVE-2026-26007: cryptography Subgroup Attack Due to Missing Subgroup Validation for SECT Curves

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.

HighCVSS 8.2Not KEV-listedUpdated
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Glexia's TakeAutomated analysis

Security readout for executives and security teams

Python cryptography versions before 46.0.5 may accept specially crafted public keys on SECT elliptic curves. In affected ECDH or ECDSA workflows, this can leak bits of a private key or allow forged signatures. The issue is serious, but sources limit impact to SECT curves and do not show active exploitation. Exposure is most likely in Python applications or dependencies using pyca cryptography before 46.0.5 with SECT curves for ECDH, ECDSA, or public-key loading from untrusted sources. Applications using other curve families are not identified as affected in the provided sources. Treat as high priority where Python services process external cryptographic public keys or rely on SECT-curve signing or key exchange. Patch during the next urgent maintenance window for exposed services; lower priority may be reasonable where SECT curves are not used. Mitigation focus: Upgrade pyca cryptography to 46.0.5 or later.; Review vendor advisories for downstream patched packages.; Avoid accepting untrusted SECT public keys until patched..

Prepared

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-345: Exact CWE lookup

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cwe · low confidence lookup

CWE-354: Exact CWE lookup

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CVE-2026-26007 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.2 (4.0)
Known Exploited
No
Published

Vector: 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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
3ADP providers
26Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.2CVSS 4.0HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N——GitHub_M
7.4CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N2.25.2redhat-SADP

Vulnerability scoring details

Base CVSS 4.0 score

8.2High
CVSS 4.0 vector shape for CVE-2026-26007Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: 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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPcryptography: cryptography Subgroup Attack Due to Missing Subgroup Validation for SECT Curves
other:Red Hat severity ratingcvssV3_1
  • 2026-02-10T22:01:01.036Z: Reported to Red Hat.
  • 2026-02-10T21:42:56.471Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
pycacryptography< 46.0.5Listed
Weakness

CWE details

CWE-345CWE-354

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-345 · source CWE mapping

Insufficient Verification of Data Authenticity

Insufficient Verification of Data Authenticity represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs
CWE-354 · source CWE mapping

Improper Validation of Integrity Check Value

Improper Validation of Integrity Check Value represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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