JWS and JWT signature validation vulnerability with special characters
Impact
Jsrsasign supports JWS(JSON Web Signatures) and JWT(JSON Web Token) validation. However JWS or JWT signature with non Base64URL encoding special characters or number escaped characters may be validated as valid by mistake.
For example, even if a string of non Base64URL encoding characters such as !@$% or \11 is inserted into a valid JWS or JWT signature value string, it will still be a valid JWS or JWT signature by mistake.
When jsrsasign's JWS or JWT validation is used in OpenID connect or OAuth2, this vulnerability will affect to authentication or authorization.
By our internal assessment, CVSS 3.1 score will be 8.6. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
Patches
Users validate JWS or JWT signatures should upgrade to 10.5.25.
Workarounds
Validate JWS or JWT signature if it has Base64URL and dot safe string before executing JWS.verify() or JWS.verifyJWT() method.
ACKNOWLEDGEMENT
Thanks to Adi Malyanker and Or David for this vulnerability report. Also thanks for Snyk security team for this coordination.
References
https://github.com/kjur/jsrsasign/releases/tag/10.5.25 https://github.com/kjur/jsrsasign/security/advisories/GHSA-3fvg-4v2m-98jf kjur's advisories https://github.com/advisories/GHSA-3fvg-4v2m-98jf github advisories https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-25898 https://kjur.github.io/jsrsasign/api/symbols/KJUR.jws.JWS.html#.verifyJWT https://kjur.github.io/jsrsasign/api/symbols/KJUR.jws.JWS.html#.verify https://kjur.github.io/jsrsasign/api/symbols/global__.html#.isBase64URLDot https://github.com/kjur/jsrsasign/wiki/Tutorial-for-JWS-verification https://github.com/kjur/jsrsasign/wiki/Tutorial-for-JWT-verification https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-2869122
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | jsrsasign | >= 4.8.0, < 10.5.25 | 10.5.25 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2022-25898
- https://github.com/kjur/jsrsasign/commit/4536a6e9e8bcf1a644ab7c07ed96e453347dae41
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-25898
- https://github.com/kjur/jsrsasign
- https://github.com/kjur/jsrsasign/releases/tag/10.5.25
- https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSBOWER-2935898
- https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSBOWERGITHUBKJUR-2935897
- https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-2935896
- https://snyk.io/vuln/SNYK-JS-JSRSASIGN-2869122
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N- Weakness (CWE)
CWE-347- Platform
- npm
- Package
jsrsasign- Disclosed
- 25.06.2022
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-3fvg-4v2m-98jf - CC BY 4.0
Vulnerability history: jsrsasign
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 14
- First → latest
- 06.2020 03.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 4
- High 7
- Medium 2
- Low 1
Disclosures per year
- 2020: 4
- 2021: 1
- 2022: 2
- 2023: 0
- 2024: 1
- 2025: 0
- 2026: 6
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