SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2025-27144

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.

MEDIUM 6.6EPSS 0.39%

Does this matter?

Lower severity and a low EPSS score (0.39%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 4.0
6.6 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.39% probability · 33th percentile
CISA KEV
Not listed
Weakness
CWE-770
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.