---
id: CVE-2026-63770
title: >-
  Glance through 0.8.5 contains an IP address spoofing vulnerability in the
  authentication handler that allows unauthenticated attackers to bypass
  brute-force lockout protections by supplying arbitrary values in the
  X-Forwarded-For request…
summary: >-
  Glance through 0.8.5 contains an IP address spoofing vulnerability in the
  authentication handler that allows unauthenticated attackers to bypass
  brute-force lockout protections by supplying arbitrary values in the
  X-Forwarded-For request…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-348
published: '2026-07-20'
updated: '2026-08-21'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-63770'
references:
  - url: >-
      https://github.com/glanceapp/glance/commit/3f20e8d9d0b1983892632649f35fd00c7b4ea8b6
    label: disclosure@vulncheck.com
  - url: 'https://github.com/glanceapp/glance/issues/1031'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/glanceapp/glance/pull/1033'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/glance-ip-spoofing-authentication-brute-force-protection-bypass
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00295
epssPercentile: 0.19759
ingestedAt: '2026-08-22T13:32:35.563Z'
---

## Overview

Glance through 0.8.5 contains an IP address spoofing vulnerability in the authentication handler that allows unauthenticated attackers to bypass brute-force lockout protections by supplying arbitrary values in the X-Forwarded-For request header when the server proxied option is enabled. Attackers can manipulate the leftmost value of the X-Forwarded-For header to make each login attempt appear to originate from a distinct IP address, preventing the per-IP failed-login counter from reaching the lockout threshold and enabling unlimited credential guessing against the authentication endpoint.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.