# CVE-2026-22700: RustCrypto Has Insufficient Length Validation in decrypt() in SM2-PKE > Attackers can crash applications using RustCrypto's SM2 decryption by sending malformed ciphertext, causing a denial of service. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** No - **Published:** 10 Jan 2026 - **Updated:** 12 Jan 2026 - **Also known as:** GHSA-j9xq-69pf-pcm8 ## 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 (Improper Input Validation) ## Which versions are affected by CVE-2026-22700? 2 open source packages ship an affected version, including sm2. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `sm2` | crates.io | From 0.14.0-pre.0 to 0.14.0-rc.4 | None | | `sm2` | crates.io | From 0.14.0-pre.0 to 0.14.0-rc.4 | None | Products: 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. ## 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](https://insights.sbomify.com/CVE-2026-22698/): RustCrypto SM2-PKE has 32-bit Biased Nonce Vulnerability (high 8.7) - [CVE-2026-22699](https://insights.sbomify.com/CVE-2026-22699/): RustCrypto SM2-PKE has Unchecked AffinePoint Decoding (unwrap) in decrypt() (high 7.5) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-22700 and fix it if it is affected. What it is: 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. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22700 exists. Affected packages and fixed versions: - sm2 (crates.io): affected from 0.14.0-pre.0 up to 0.14.0-rc.4; no fix listed - sm2 (crates.io): affected from 0.14.0-pre.0 up to 0.14.0-rc.4; no fix listed Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-22700/ (Markdown: https://insights.sbomify.com/CVE-2026-22700/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-22700 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-22700 - OSV: https://osv.dev/vulnerability/CVE-2026-22700 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-22700/ Summaries are generated and may contain mistakes; the official description above is the record.