CVE-2026-54673: electron-updater: Cross-origin redirect leaks `PRIVATE-TOKEN` and mixed-case `Authorization` credentials in `builder-util-runtime`

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-06-30 · updated 2026-08-26
Weakness: CWE-200

Description

electron-updater allows for automatic updates for Electron apps. Prior to 9.7.0, the HTTP redirect handler (HttpExecutor.prepareRedirectUrlOptions) only stripped a credential header whose key string matched exactly lowercase "authorization", exposing credentials. Other credential-bearing headers — most notably PRIVATE-TOKEN (used by GitLab's personal access token flow) and mixed-case Authorization (used by GitLab's Bearer/OAuth flow) — were not stripped and could be forwarded to an attacker-controlled cross-origin redirect destination. This issue has been fixed in version 9.7.0.

Affected products

electron-userland builder-util-runtime: before 9.7.0 — fixed in 9.7.0
electron-userland electron-builder: before 26.15.0 — fixed in 26.15.0

How to fix

Upgrade to a fixed version: electron-userland builder-util-runtime 9.7.0; electron-userland electron-builder 26.15.0. Check the vendor advisory for mitigations.

References

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