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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-22700: 0.31% estimated exploitation activity in the next 30 days; percentile 24.14 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A denial-of-service vulnerability exists in the SM2 public-key encryption (PKE) implementation: the decrypt() path performs unchecked slice::splitat 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. Affected Component / Versions - File: src/pke/decrypting.rs - Functions: DecryptingKey::decryptdigest/decrypt/decryptder, internal decrypt() implementation - Affected releases: - sm2 0.14.0-rc.0 (https://crates.io/crates/sm2/0.14.0-rc.0) - sm2 0.14.0-pre.0 (https://crates.io/crates/sm2/0.14.0-pre.0) Details The vulnerability is located in the file sm2/src/pke/decrypting.rs. The fundamental cause of the vulnerability is that the decryption function does not strictly check the ciphertext's format and length information. Consequently, a maliciously crafted ciphertext can trigger Rust's…

Published by the source

13 Jan 2026, 15:02 UTC

Last modified by the source

13 Jan 2026, 15:02 UTC

Source last checked

26 Oct 2026, 15:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-j9xq-69pf-pcm8

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# Patch Next advisory brief: CVE-2026-22700

Advisory: RustCrypto Has Insufficient Length Validation in decrypt() in SM2-PKE
IDs: CVE-2026-22700, GHSA-j9xq-69pf-pcm8
Record: https://patchnext.com/advisories/cve-2026-22700 (revision 1, source checked 26 Oct 2026, 15:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io sm2: affected >= 0.14.0-pre.0, <= 0.14.0-rc.4

## Suggested inspection (read-only)
- crates.io sm2: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on sm2.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-j9xq-69pf-pcm8 (GitHub-reviewed advisory GHSA-j9xq-69pf-pcm8 lists affected ranges: crates.io sm2 >=0.14.0-pre.0 <=0.14.0-rc.4)

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