# CVE-2026-62374: SD JWT JS: Tampered disclosures silently dropped instead of rejected


- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 29 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-f9j6-8p6x-r9j6

## What is CVE-2026-62374?

CVE-2026-62374 is a high-severity vulnerability in openwallet-foundation @sd-jwt/core, published on 29 Oct 2026. 

### Official description

SD JWT JS is a JavaScript implementation of the Selective Disclosure JWT (SD-JWT) specification. In version 0.19.0 and earlier, `@sd-jwt/decode`, also used by `@sd-jwt/core`, silently drops a tampered Disclosure whose digest no longer matches the Issuer-signed `_sd` array and returns a reduced claim set, reporting success while the Issuer signature remains valid. Both a tampered Disclosure that remains valid JSON and a Disclosure containing invalid UTF-8 bytes reach this silent-drop behavior. In the latter case, the `TextDecoder / Buffer` decoding path substitutes U+FFFD replacement characters, recovering syntactically valid disclosure data instead of rejecting the malformed input. This violates RFC 9901 section 7.1 step 5, which requires rejection of unreferenced Disclosures, and section 7.1 step 3 / section 4.2.1, which require rejection of invalid Disclosures. A malicious holder can exploit this omission primitive, including through `SDJwtInstance.verify()` when key binding is required. An on-path attacker can also tamper with a Disclosure when the relying party does not enforce key binding; enforced key binding rejects on-path tampering because it invalidates the KB-JWT `sd_hash` binding. If the relying party defaults to allowing access when a constraining age, role, or restriction claim is absent, the silent claim reduction can change an authorization decision without an error. This issue is fixed in `@sd-jwt/core` version 0.20.0; no patched version of the standalone `@sd-jwt/decode` package is identified.

Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions), CWE-176 (Improper Handling of Unicode Encoding)

## Which versions are affected by CVE-2026-62374?


## How do I fix CVE-2026-62374?

No fix has been published for CVE-2026-62374 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-62374 being exploited?

There is no known exploitation of CVE-2026-62374 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-62374 and fix it if it is affected.

What it is: CVE-2026-62374 is a high-severity vulnerability in openwallet-foundation @sd-jwt/core, published on 29 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-62374 in the wild and no public exploit code.

Affected product: openwallet-foundation @sd-jwt/core. 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-2026-62374/ (Markdown: https://insights.sbomify.com/CVE-2026-62374/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-62374
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-62374
- OSV: https://osv.dev/vulnerability/CVE-2026-62374

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-62374/
Summaries are generated and may contain mistakes; the official description above is the record.