# CVE-2026-63770: Glance 0.8.5 IP Spoofing Authentication Brute-Force Protection Bypass

> Attackers can bypass brute-force lockout protections in Glance by spoofing IP addresses via the X-Forwarded-For header when proxying is enabled.

- **Severity:** High 8.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Jul 2026
- **Updated:** 21 Aug 2026
- **Also known as:** GHSA-jmgq-484h-mrfw

## What is CVE-2026-63770?

CVE-2026-63770 is a high-severity vulnerability in glanceapp glance, published on 20 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-348 (Use of Less Trusted Source)

## Which versions are affected by CVE-2026-63770?


## How do I fix CVE-2026-63770?

No fix has been published for CVE-2026-63770 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-63770 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-63770 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-63770 and fix it if it is affected.

What it is: CVE-2026-63770 is a high-severity vulnerability in glanceapp glance, published on 20 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-63770 exists.

Affected product: glanceapp glance. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-63770/ (Markdown: https://insights.sbomify.com/CVE-2026-63770/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63770
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63770
- OSV: https://osv.dev/vulnerability/CVE-2026-63770

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63770/
Summaries are generated and may contain mistakes; the official description above is the record.