GHSA-j8h8-75h3-jg53

Source

https://github.com/advisories/GHSA-j8h8-75h3-jg53

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-j8h8-75h3-jg53/GHSA-j8h8-75h3-jg53.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-j8h8-75h3-jg53

Aliases

Published

2026-05-14T13:13:39Z

Modified

2026-06-25T23:11:31Z

Severity

5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator
6.9 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N CVSS Calculator

Summary

Fleet has a rate limiting bypass via untrusted client IP headers

Details

Impact

Fleet trusted client-supplied IP address headers when determining the source IP for incoming requests. This allowed authenticated and unauthenticated clients to spoof their apparent IP address and bypass per-IP rate limiting controls.

Fleet determines a client’s public IP address using HTTP headers such as:

X-Forwarded-For
X-Real-IP
True-Client-IP

These headers were trusted without validation. An attacker could supply arbitrary values in these headers, causing Fleet to treat each request as originating from a different IP address.

This could allow an attacker to bypass per-IP rate limits and increase the effectiveness of brute-force or password-spraying attempts against authentication endpoints.

This issue does not allow authentication bypass, privilege escalation, data exposure, or remote code execution on its own.

Workarounds

Run Fleet behind a trusted reverse proxy or load balancer that overwrites client IP headers.

For more information

If you have any questions or comments about this advisory:

Email us at security@fleetdm.com Join #fleet in osquery Slack

Credits

We thank @fuzzztf for responsibly reporting this issue.

Database specific

{
    "cwe_ids":  [
        "CWE-290"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-05-14T13:13:39Z",
    "nvd_published_at":  "2026-05-14T20:17:01Z",
    "severity":  "MODERATE"
}

References

Affected packages

Go / github.com/fleetdm/fleet/v4

Package

Name: github.com/fleetdm/fleet/v4; View open source insights on deps.dev
Purl: pkg:golang/github.com/fleetdm/fleet/v4

Affected ranges

Type: SEMVER
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

4.80.1

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-j8h8-75h3-jg53/GHSA-j8h8-75h3-jg53.json"