Vulnerability Details CVE-2025-62706
                Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.5, Authlib’s JWE zip=DEF path performs unbounded DEFLATE decompression. A very small ciphertext can expand into tens or hundreds of megabytes on decrypt, allowing an attacker who can supply decryptable tokens to exhaust memory and CPU and cause denial of service. This issue has been patched in version 1.6.5. Workarounds for this issue involve rejecting or stripping zip=DEF for inbound JWEs at the application boundary, forking and add a bounded decompression guard via decompressobj().decompress(data, MAX_SIZE)) and returning an error when output exceeds a safe limit, or enforcing strict maximum token sizes and fail fast on oversized inputs; combine with rate limiting.
                
                    Exploit prediction scoring system (EPSS) score
                    
                        
                            EPSS Score 0.0
                        
                    
                    
                        
                            EPSS Ranking 13.2%
                        
                    
                 
                
                    CVSS Severity
                    
                        
                            CVSS v3 Score 6.5
                        
                    
                    
                 
                
                
                
                    
                
                
                    
                        Products affected by CVE-2025-62706
                        
                            
                                
                                - 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:-
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.10
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.11
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.12
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.12.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.13
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.14
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.14.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.14.2
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.14.3
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.15
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.15.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.15.2
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.15.3
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.15.4
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.15.5
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.15.6
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.2
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.2.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.3
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.4
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.4.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.5
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.5.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.6
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.7
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.8
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:0.9
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.0.0
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.0.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.1.0
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.2.0
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.2.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.3.0
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.3.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.3.2
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.4.0
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.4.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.5.0
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.5.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.5.2
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.6.0
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.6.1
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.6.2
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.6.3
                                         
 
- 
                                    
                                    
                                        
                                            cpe:2.3:a:authlib:authlib:1.6.4