PatchSiren cyber security CVE debrief
CVE-2026-56676 decolua CVE debrief
CVE-2026-56676 is a high-severity vulnerability in 9Router, an AI router & token saver. Prior to version 0.5.2, 9router validates image URLs by resolving the host before fetching, but open-sse/translator/concerns/image.js performs the later server-side image fetch with a separate DNS resolution. An authenticated attacker with access to the LLM proxy can use a vision-capable model and an attacker-controlled DNS name that first resolves to a public IP and then rebinds to an internal address, allowing server-side requests to internal-only HTTP services. This vulnerability requires authentication and access to the LLM proxy, but can allow for server-side requests to internal-only HTTP services. The CVE record was published on 2026-07-10T16:16:34.923Z and has not been modified since then. The NVD entry is currently Deferred.
- Vendor
- decolua
- Product
- 9router
- CVSS
- HIGH 7.4
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-07-10
- Original CVE updated
- 2026-07-13
- Advisory published
- 2026-07-10
- Advisory updated
- 2026-07-13
Who should care
Users of 9Router, an AI router & token saver, should be aware of this high-severity vulnerability and take steps to mitigate it. This vulnerability requires authentication and access to the LLM proxy, but can allow for server-side requests to internal-only HTTP services. Affected operators, platform administrators, vulnerability management teams, and security teams should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
Technical summary
The vulnerability exists in 9Router, an AI router & token saver, due to inconsistent DNS resolution. The application validates image URLs by resolving the host before fetching, but open-sse/translator/concerns/image.js performs the later server-side image fetch with a separate DNS resolution. This allows an authenticated attacker with access to the LLM proxy to use a vision-capable model and an attacker-controlled DNS name that first resolves to a public IP and then rebinds to an internal address. This enables server-side requests to internal-only HTTP services.
Defensive priority
High
Recommended defensive actions
- Upgrade to version 0.5.2 or later
- Restrict access to the LLM proxy
- Monitor for suspicious activity
- Implement compensating controls, such as firewall rules or intrusion detection systems
- Review compensating controls for exposed systems while remediation is scheduled and verified
- Check relevant monitoring, detection, and logs for exposed assets that need extra review
- Track exceptions, retest remediated assets, and close the item only after evidence is documented
Evidence notes
The CVE record was published on 2026-07-10T16:16:34.923Z and has not been modified since then. The NVD entry is currently Deferred. There is limited information available about the vulnerability, and defenders should verify the affected scope and severity with the vendor. The vulnerability exists in 9Router, an AI router & token saver, due to inconsistent DNS resolution. This allows an authenticated attacker with access to the LLM proxy to use a vision-capable model and an attacker-controlled DNS name that first resolves to a public IP and then rebinds to an internal address, enabling server-side requests to internal-only HTTP services.
Sources and references
Verified primary and authoritative sources
-
CVE-2026-56676 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-56676
CVE Program - Official CVE Program record with source-provided CVE metadata.
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CVE-2026-56676 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-56676
NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.
Supplemental references
-
Source reference
Unverified legacy reference
URL: https://github.com/decolua/9router/commit/c7d07448c58bec1200741de0b73305b860416b82
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Source reference
Unverified legacy reference
URL: https://github.com/decolua/9router/releases/tag/v0.5.2
-
Source reference
Unverified legacy reference
URL: https://github.com/decolua/9router/security/advisories/GHSA-cmhj-wh2f-9cgx
Methodology and review provenance
AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.