# CVE-2026-33894: Forge has signature forgery in RSA-PKCS due to ASN.1 extra field

> Attackers can forge RSA-PKCS#1 v1.5 signatures in node-forge by exploiting ASN.1 parsing flaws, bypassing signature verification.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Mar 2026
- **Updated:** 10 Sep 2026
- **Also known as:** CLEANSTART-2026-NK73842, CLEANSTART-2026-ZI53736, MINI-4fx3-46r7-9rwx, MINI-5rxg-2777-xw37, MINI-5w8g-7hj3-x7pf, MINI-646m-fh43-83qm, MINI-6697-8rx4-6wc5, MINI-75v3-xr2f-8q35, MINI-c89r-6hx3-3573, MINI-fr44-jpqw-8273, MINI-fwqq-h7hv-66ff, MINI-hr2v-fc7q-j8vq, MINI-jgxr-32vv-gm4x, MINI-m33p-qxcm-r9xf, MINI-m3mg-3rgp-gf4g, MINI-mjgf-8j57-fv66, MINI-qm72-q8p4-85c7, MINI-vjpc-9pj9-vfx9, MINI-w478-77c8-7vf3, MINI-xj5h-j367-f589, MINI-xqfj-422f-44fh, ROOT-APP-NPM-CVE-2026-33894, UBUNTU-CVE-2026-33894

## What is CVE-2026-33894?

CVE-2026-33894 is a high-severity vulnerability in digitalbazaar forge, published on 27 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Forge (also called `node-forge`) is a native implementation of Transport Layer Security in JavaScript. Prior to version 1.4.0, RSASSA PKCS#1 v1.5 signature verification accepts forged signatures for low public exponent keys (e=3). Attackers can forge signatures by stuffing “garbage” bytes within the ASN structure in order to construct a signature that passes verification, enabling Bleichenbacher style forgery. This issue is similar to CVE-2022-24771, but adds bytes in an addition field within the ASN structure, rather than outside of it.  Additionally, forge does not validate that signatures include a minimum of 8 bytes of padding as defined by the specification, providing attackers additional space to construct Bleichenbacher forgeries. Version 1.4.0 patches the issue.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature), CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-33894?

It affects 1 product.


Products: Digitalbazaar Forge.

## How do I fix CVE-2026-33894?

Upgrade to a fixed version.

## Is CVE-2026-33894 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33894 exists.

## Other vulnerabilities in digitalbazaar forge

- [CVE-2020-7720](https://insights.sbomify.com/CVE-2020-7720/): Prototype Pollution (critical 9.8)
- [CVE-2025-66031](https://insights.sbomify.com/CVE-2025-66031/): node-forge ASN.1 Unbounded Recursion (high 8.7)
- [CVE-2025-12816](https://insights.sbomify.com/CVE-2025-12816/): CVE-2025-12816 (high 8.6)
- [CVE-2026-33891](https://insights.sbomify.com/CVE-2026-33891/): Forge has Denial of Service via Infinite Loop in BigInteger.modInverse() with Zero Input (high 7.5)
- [CVE-2026-33895](https://insights.sbomify.com/CVE-2026-33895/): Forge has signature forgery in Ed25519 due to missing S > L check (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33894 and fix it if it is affected.

What it is: CVE-2026-33894 is a high-severity vulnerability in digitalbazaar forge, published on 27 Mar 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-2026-33894 exists.

Affected product: digitalbazaar forge. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-33894/ (Markdown: https://insights.sbomify.com/CVE-2026-33894/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33894
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33894
- OSV: https://osv.dev/vulnerability/CVE-2026-33894

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33894/
Summaries are generated and may contain mistakes; the official description above is the record.