security: CVE-2026-26007 + others - cryptography 43.0.1 - upgrade to 46.0.6

[vks-archastro]

Summary

cryptography==43.0.1 in apiserver/requirements/base.txt has multiple vulnerabilities. The most critical is an ECDH subgroup attack (CVE-2026-26007, HIGH) affecting SECT curves, and a secondary OpenSSL vulnerability (CVE-2024-12797). Fix requires upgrade to cryptography>=46.0.6.

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Vulnerabilities

CVE-2026-26007 — ECDH Subgroup Attack (HIGH)

• Advisory: GHSA-r6ph-v2qm-q3c2
• CVSS: HIGH (CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N)
• Fixed in: 46.0.5
• Description: public_key_from_numbers(), EllipticCurvePublicNumbers.public_key(), load_der_public_key(), and load_pem_public_key() do not verify that the public key point belongs to the expected prime-order subgroup of the curve. For SECT curves (cofactor > 1), an attacker supplying a small-subgroup public key can leak bits of the victim's ECDH private key, and forge ECDSA signatures. Only SECT curves are affected.

CVE-2024-12797 — Vulnerable OpenSSL in wheels (LOW)

• Advisory: GHSA-79v4-65xg-pq4g
• Fixed in: 44.0.1
• Description: The statically linked OpenSSL in cryptography 42.0.0–44.0.0 wheels is vulnerable. Affects users installing from PyPI wheels (not sdist builds).

CVE-2026-34073 — Incomplete DNS Name Constraint Enforcement (LOW)

• Advisory: GHSA-m959-cc7f-wv43
• Fixed in: 46.0.6
• Description: DNS name constraints were only validated against SANs, not the peer name during validation. Allows a peer named bar.example.com to validate against *.example.com even if a parent cert excludes bar.example.com. Requires uncommon X.509 topology to exploit.

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Package Details

• Package: cryptography
• Current version: 43.0.1
• Fixed version: 46.0.6 (addresses all three CVEs)
• File: apiserver/requirements/base.txt

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Severity Assessment

The ECDH subgroup attack (CVE-2026-26007) is HIGH severity but only affects SECT curves (e.g., sect163k1, sect233r1). NIST P-curves (secp256r1, secp384r1) and Curve25519 are not affected. Plane uses cryptography primarily for token signing and general cryptographic operations — if SECT curves are not used (typical for web applications), practical exploitability is very low.

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Affected Code

• apiserver/ — any code using ECDH key exchange or ECDSA with SECT curves
• Any certificate loading with load_pem_public_key() / load_der_public_key() followed by ECDH

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Triage Reasoning

Escalating rather than auto-fixing because:

1. Major version jump (43.0.1 → 46.0.6): need to verify API compatibility and check for any deprecations impacting the codebase
2. The HIGH CVE only affects SECT curves — human should assess whether Plane uses these before prioritizing urgency
3. May require updating the Rust toolchain and other build dependencies

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Recommended Action

1. Assess curve usage: Search the codebase for SECT curve names (sect163, sect233, sect283, sect409, sect571, SECT_*) — if none found, risk from CVE-2026-26007 is effectively zero
2. Upgrade to cryptography==46.0.6 in apiserver/requirements/base.txt
3. Run tests, especially auth and any crypto-heavy flows
4. Review the cryptography changelog for breaking changes: https://cryptography.io/en/latest/changelog/

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Mitigations In Place

• If Plane uses only NIST P-curves or Curve25519/Ed25519 (typical web app pattern), CVE-2026-26007 does not apply
• CVE-2024-12797 and CVE-2026-34073 are LOW severity