CVE-2026-22700 RustCrypto Has Insufficient Length Validation in decrypt() in SM2-PKE

What is CVE-2026-22700?

CVE-2026-22700 is a high-severity denial of service vulnerability in RustCrypto elliptic-curves, published on 10 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

RustCrypto: Elliptic Curves is general purpose Elliptic Curve Cryptography (ECC) support, including types and traits for representing various elliptic curve forms, scalars, points, and public/secret keys composed thereof. In versions 0.14.0-pre.0 and 0.14.0-rc.0, a denial-of-service vulnerability exists in the SM2 public-key encryption (PKE) implementation: the decrypt() path performs unchecked slice::split_at operations on input buffers derived from untrusted ciphertext. An attacker can submit short/undersized ciphertext or carefully-crafted DER-encoded structures to trigger bounds-check panics (Rust unwinding) which crash the calling thread or process. This issue has been patched via commit e60e991.

Weakness: CWE-20

Which versions are affected by CVE-2026-22700?

2 open source packages ship an affected version, including sm2. It affects 1 product.

Products include Rustcrypto Sm2 Elliptic Curve.

How do I fix CVE-2026-22700?

No fix has been published for CVE-2026-22700 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-22700 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22700 exists.

Other vulnerabilities in RustCrypto elliptic-curves

• CVE-2026-22698 RustCrypto SM2-PKE has 32-bit Biased Nonce Vulnerability High 8.7
• CVE-2026-22699 RustCrypto SM2-PKE has Unchecked AffinePoint Decoding (unwrap) in decrypt() High 7.5

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-j9xq-69pf-pcm8.