What’s Vulnerable › Vulnerabilities

CVE-2026-44373: Nitro: Proxy scope bypass via percent-encoded path traversal in `routeRules`

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-13 · updated 2026-10-26
• Weakness: CWE-22

Description

Nitro is a next generation server toolkit. Prior to 3.0.260429-beta, an attacker could bypass a proxy route rule by sending percent-encoded path traversal (..%2f) in the URL, causing Nitro to forward a request that the upstream resolved outside the configured scope. This vulnerability is fixed in 3.0.260429-beta.

Affected products

• nitrojs nitro: before 2.13.4; from 2.13.4 (excl.) before 3.0.260429 — fixed in 2.13.4, 3.0.260429

How to fix

Upgrade to a fixed version: nitrojs nitro 2.13.4, 3.0.260429. Check the vendor advisory for mitigations.

References

• https://github.com/nitrojs/nitro/pull/4222
• https://github.com/nitrojs/nitro/pull/4223
• https://github.com/nitrojs/nitro/releases/tag/v2.13.4
• https://github.com/nitrojs/nitro/releases/tag/v3.0.260429-beta
• https://github.com/nitrojs/nitro/security/advisories/GHSA-5w89-w975-hf9q

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