CVE-2026-91164: Access Control Flaw (CVSS 4.3)

Description

Warpgate is an open source SSH, HTTPS and MySQL bastion host for Linux. From 0.23.0 until 0.27.3, HTTP API token authentication resolves ConfigProvider::validate_api_token into RequestAuthorization::UserToken without enforcing the owning user's allowed_ip_ranges against the trusted client address in warpgate-protocol-http/src/common.rs. An attacker holding a leaked, phished, or exfiltrated X-Warpgate-Token can therefore use it from a prohibited network location. Deployments without allowed_ip_ranges are unaffected, and HTTP target proxying plus SSH, MySQL, PostgreSQL, RDP, VNC, and Kubernetes paths do not accept this vulnerable HTTP token flow. This issue is fixed in version 0.27.3.

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CVSS v3.1 Score

4.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

EPSS — Exploit Prediction

0.0042

Probability of exploitation

0.34%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-284 CWE-284

CWE-863 Incorrect Authorization

References

Other References

https://github.com/warp-tech/warpgate/commit/8cb33a1a7c447ab0cde3a1ee9f95bf9dde905482 https://github.com/warp-tech/warpgate/pull/2356 https://github.com/warp-tech/warpgate/releases/tag/v0.27.3 https://github.com/warp-tech/warpgate/security/advisories/GHSA-qmr2-wp96-h9ff

Frequently Asked Questions

What is CVE-2026-91164? +

Warpgate is an open source SSH, HTTPS and MySQL bastion host for Linux. From 0.23.0 until 0.27.3, HTTP API token authentication resolves ConfigProvider::validate_api_token into RequestAuthorization::UserToken without enforcing the owning user's allowed_ip_ranges against the trusted client address in warpgate-protocol-http/src/common.rs. An attacker holding a leaked, phished, or exfiltrated X-Warpgate-Token can therefore use it from a prohibited network location. Deployments without allowed_ip_ranges are unaffected, and HTTP target proxying plus SSH, MySQL, PostgreSQL, RDP, VNC, and Kubernetes paths do not accept this vulnerable HTTP token flow. This issue is fixed in version 0.27.3. It has a CVSS v3.1 base score of 4.3 (MEDIUM).

How severe is CVE-2026-91164? +

CVE-2026-91164 has a CVSS v3.1 score of 4.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0042, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-91164? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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