Vulnerability in sm-crypto (CVE-2026-73567)
Summary
Vulnerability in sm-crypto (CVE-2026-73567). Confidential information can be exposed externally. Exploitable via SecureRandom. Mitigation: upgrade to 0.5.0 or later.
Original description
The description as published by the source.
Summary
sm-crypto (npm package 0.4.0, the latest release, published 2026-01-20)
generates SM2 private keys and signing ephemeral scalars from a single
module-wide RNG instance (src/sm2/utils.js: const rng = new SecureRandom()).
SecureRandom is jsbn's PRNG, which seeds an ARC4 stream from
window.crypto.getRandomValues when available. In Node.js — sm-crypto's
primary runtime — window is undefined, so the CSPRNG branch is skipped
and the seed pool is instead filled from Math.random() (V8 xorshift128+,
recoverable from a few outputs) plus new Date().getTime() (wall clock,
attacker-estimable).
Node does expose Web Crypto as globalThis.crypto, but jsbn checks
window.crypto, not globalThis.crypto, so the secure path is never taken.
Consequently every SM2 private key produced by the default
sm2.generateKeyPairHex() and every signing ephemeral scalar is derived from
non-cryptographic sources and is predictable by an attacker who can observe
a few Math.random() outputs and estimate the generation time.
This is the library's default (no-argument) path; no caller-selected
parameter or configuration is required to trigger it. It is reproduced
end-to-end against the unmodified real npm packages (sm-crypto@0.4.0 +
jsbn@1.1.0); the PoC below runs against the real installed package, not a
copy. The defect is still present on the latest published version (0.4.0) and
is not covered by any existing JuneAndGreen/sm-crypto issue (0 af…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-73567 has been found in sm-crypto.
Attackers can target a specific entry point like SecureRandom over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 9.1/10.
What to do: upgrade sm-crypto to 0.5.0 or later.
If unsure, ask your IT team or search "sm-crypto CVE-2026-73567" on the vendor's site.
CVE-2026-73567 (sm-crypto) — CWE-338 / CVSS v3 9.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: SecureRandom / window.crypto.getRandomValues / window / undefined
Patched: 0.5.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-338) exists in sm-crypto. Attackers reach the vulnerable code path via SecureRandom without authentication.
Check the vendor advisory for the affected versions of sm-crypto. Attack surface: SecureRandom / window.crypto.getRandomValues / window / undefined.
Severity: Critical (CVSS 9.1/10). Confidential information can be exposed externally.
Update to 0.5.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'sm-crypto' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'sm-crypto' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
sm-cryptoを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade sm-crypto to 0.5.0ステージング環境で 0.5.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。