GitHub CLI (gh) performed a hidden token masking feature that only obscured characters after the last underscore in the token string. As a result, the suffix of fine‑grained personal access tokens and GitHub App tokens was visible in terminal and CI command output. This partial disclosure allows an observer with access to such output to see a fragment of a credential, which could be used in combination with other leaked data or brute‑forced to compromise the token. The vulnerability does not grant code execution or administrator privileges; it simply leaks sensitive token data. The weakness is classified as CWE‑201, information exposure.

Affected systems include the GitHub CLI (cli:cli) running any version prior to 2.97.0. Authenticated users who ran gh auth status without the --show-token flag with a fine‑grained personal access token (github_pat_*), GitHub App installation or user access tokens (ghs_*, ghu_*) or the Actions GITHUB_TOKEN may see parts of their tokens in terminal or logs. Classic tokens such as gho_* and ghp_* are not affected due to their underscore‑free format.

The CVSS score of 3.3 indicates low severity, reflecting the information‑exposure nature rather than a direct exploitation pathway. EPSS data is not available, so the real‑world probability of exploitation is uncertain. The issue is not listed in the CISA KEV catalog. Likely attack scenarios involve a human operator or CI system capturing console output or logs where gh auth status is executed without the --show-token flag. An attacker who obtains a token fragment may still need additional information to fully compromise an account, but the partial disclosure increases the attack surface and risk of credential misuse.