CVE-2026-44373

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

MEDIUM
5.3
CVSS Score
Published: May 13, 2026 at 08:26 PM UTC
Updated: October 26, 2026 at 05:10 PM UTC
2 products affected across 2 vendorsNitroNitro

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.5%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.13.42.13.4 < v < 3.0.260429
v < 2.13.4v < 3.0.260429-beta
Affected range stops below 2.13.4, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.0.260429-beta, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (5)

x_refsource_CONFIRMThird Party Advisory
Source: cverecord
https://github.com/nitrojs/nitro/security/advisories/GHSA-5w89-w975-hf9q
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/nitrojs/nitro/pull/4222
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/nitrojs/nitro/pull/4223
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/nitrojs/nitro/releases/tag/v2.13.4
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/nitrojs/nitro/releases/tag/v3.0.260429-beta

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-22

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