Go JOSE's Parsing Vulnerable to Denial of Service
Go JOSE provides an implementation of the Javascript Object Signing and Encryption set of standards in Go, including support for JSON Web Encryption (JWE), JSON Web Signature (JWS), and JSON Web Token (JWT) standards. In versions on the 4.x branch prior to version 4.0.5, when parsing compact JWS or JWE input, Go JOSE could use excessive memory. The code used strings.Split(token, ".") to split JWT tokens, which is vulnerable to excessive memory consumption when processing maliciously crafted tokens with a large number of `.` characters. An attacker could exploit this by sending numerous malformed tokens, leading to memory exhaustion and a Denial of Service. Version 4.0.5 fixes this issue. As a workaround, applications could pre-validate that payloads passed to Go JOSE do not contain an excessive number of `.` characters.
02 / AFFECTED SOFTWARE
Affected packages
5 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
DoS in go-jose Parsing in github.com/go-jose/go-jose
### Impact When parsing compact JWS or JWE input, go-jose could use excessive memory. The code used strings.Split(token, ".") to split JWT tokens, which is vulnerable to excessive memory consumption when processing maliciously crafted tokens with a large number of '.' characters. An attacker could exploit this by sending numerous malformed tokens, leading to memory exhaustion and a Denial of Service. ### Patches Version 4.0.5 fixes this issue ### Workarounds Applications could pre-validate payloads passed to go-jose do not contain an excessive number of '.' characters. ### References This is the same sort of issue as in the golang.org/x/oauth2/jws package as CVE-2025-22868 and Go issue https://go.dev/issue/71490.
Go JOSE provides an implementation of the Javascript Object Signing and Encryption set of standards in Go, including support for JSON Web Encryption (JWE), JSON Web Signature (JWS), and JSON Web Token (JWT) standards. In versions on the 4.x branch prior to version 4.0.5, when parsing compact JWS or JWE input, Go JOSE could use excessive memory. The code used strings.Split(token, ".") to split JWT tokens, which is vulnerable to excessive memory consumption when processing maliciously crafted tokens with a large number of `.` characters. An attacker could exploit this by sending numerous malformed tokens, leading to memory exhaustion and a Denial of Service. Version 4.0.5 fixes this issue. As a workaround, applications could pre-validate that payloads passed to Go JOSE do not contain an excessive number of `.` characters.
05 / REFERENCES
Further evidence
- https://github.com/go-jose/go-jose/commit/99b346cec4e86d102284642c5dcbe9bb0cacfc22
- https://github.com/go-jose/go-jose/releases/tag/v4.0.5
- https://github.com/go-jose/go-jose/security/advisories/GHSA-c6gw-w398-hv78
- https://go.dev/issue/71490
- https://github.com/go-jose/go-jose
- https://github.com/golang/go/issues/71490
- https://nvd.nist.gov/vuln/detail/CVE-2025-27144
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/27xxx/CVE-2025-27144.json