https://cve.radiocsirt.org Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Thu, 15 Oct 2026 04:19:29 +0000 https://cve.radiocsirt.org/vuln/euvd-2026-292983 EUVD-2026-292983 https://cve.radiocsirt.org/vuln/euvd-2026-292983 https://cve.radiocsirt.org/vuln/fkie_cve-2026-41213 <p>@node-oauth/oauth2-server is a module for implementing an OAuth2 server in Node.js. The token exchange path accepts RFC7636-invalid code_verifier values (including one-character strings) for S256 PKCE flows. Because short/weak verifiers are accepted and failed verifier attempts do not consume the authorization code, an attacker who intercepts an authorization code can brute-force code_verifier guesses online until token issuance succeeds.</p> <p>@node-oauth/oauth2-server is a module for implementing an OAuth2 server in Node.js. The token exchange path accepts RFC7636-invalid code_verifier values (including one-character strings) for S256 PKCE flows. Because short/weak verifiers are accepted and failed verifier attempts do not consume the authorization code, an attacker who intercepts an authorization code can brute-force code_verifier guesses online until token issuance succeeds.</p> https://cve.radiocsirt.org/vuln/fkie_cve-2026-41213 https://cve.radiocsirt.org/vuln/ghsa-jhm7-29pj-4xvf <p><strong>Affected:</strong> npm: @node-oauth/oauth2-server</p> <p>## Summary</p> <p>The token exchange path accepts RFC7636-invalid `code_verifier` values (including one-character strings) for `S256` PKCE flows. Because short/weak verifiers are accepted and failed verifier attempts do not consume the authorization code, an attacker who intercepts an authorization code can brute-force `code_verifier` guesses online until token issuance succeeds.</p> <p>### Root cause</p> <p>1. `lib/pkce/pkce.js` (`getHashForCodeChallenge`) only checks that `verifier` is a non-empty string before hashing for `S256`; it does not enforce RFC7636 ABNF (`43..128` unreserved chars). 2. `lib/grant-types/authorization-code-grant-type.js` compares `hash(code_verifier)` to stored `codeChallenge` without validating verifier format/length. 3. In `AuthorizationCodeGrantType.handle`, authorization code revocation happens **after** verifier validation. Invalid guesses fail before revoke, so the same code can be retried repeatedly.</p> <p>## Steps to Reproduce</p> <p>### Setup</p> <p>- PKCE authorization code exists with: - `codeChallengeMethod = &#34;S256&#34;` - `codeChallenge = BASE64URL(SHA256(&#34;z&#34;))` (verifier is one character, RFC-invalid) - Attacker has intercepted the authorization code value.</p> <p>### Reproduction</p> <p>1. Send repeated token requests with guessed `code_verifier` values:</p> <p>```http POST /token HTTP/1.1 Host: oauth.example Content-Type: application/x-www-form-urlencoded</p> <p>grant_type=authorization_code&amp; client_id=client1&amp; client_secret=s3cret&amp; code=stolen-auth-code&amp; redirect_uri=https://client.exa…</p> <p><strong>Affected:</strong> npm: @node-oauth/oauth2-server</p> <p>## Summary</p> <p>The token exchange path accepts RFC7636-invalid `code_verifier` values (including one-character strings) for `S256` PKCE flows. Because short/weak verifiers are accepted and failed verifier attempts do not consume the authorization code, an attacker who intercepts an authorization code can brute-force `code_verifier` guesses online until token issuance succeeds.</p> <p>### Root cause</p> <p>1. `lib/pkce/pkce.js` (`getHashForCodeChallenge`) only checks that `verifier` is a non-empty string before hashing for `S256`; it does not enforce RFC7636 ABNF (`43..128` unreserved chars). 2. `lib/grant-types/authorization-code-grant-type.js` compares `hash(code_verifier)` to stored `codeChallenge` without validating verifier format/length. 3. In `AuthorizationCodeGrantType.handle`, authorization code revocation happens **after** verifier validation. Invalid guesses fail before revoke, so the same code can be retried repeatedly.</p> <p>## Steps to Reproduce</p> <p>### Setup</p> <p>- PKCE authorization code exists with: - `codeChallengeMethod = &#34;S256&#34;` - `codeChallenge = BASE64URL(SHA256(&#34;z&#34;))` (verifier is one character, RFC-invalid) - Attacker has intercepted the authorization code value.</p> <p>### Reproduction</p> <p>1. Send repeated token requests with guessed `code_verifier` values:</p> <p>```http POST /token HTTP/1.1 Host: oauth.example Content-Type: application/x-www-form-urlencoded</p> <p>grant_type=authorization_code&amp; client_id=client1&amp; client_secret=s3cret&amp; code=stolen-auth-code&amp; redirect_uri=https://client.exa…</p> https://cve.radiocsirt.org/vuln/ghsa-jhm7-29pj-4xvf