How severe is GHSA-ff24-4prj-gpmj?

GHSA-ff24-4prj-gpmj has a CVSS score of 7.2/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-ff24-4prj-gpmj?

GHSA-ff24-4prj-gpmj affects the following packages: github.com/getarcaneapp/arcane/backend (Go). Ecosystems affected: Go.

How do I fix GHSA-ff24-4prj-gpmj?

Update github.com/getarcaneapp/arcane/backend to 1.17.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-ff24-4prj-gpmj is resolved across your whole dependency graph.

How do I detect GHSA-ff24-4prj-gpmj in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/getarcaneapp/arcane/backend. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-ff24-4prj-gpmj if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-ff24-4prj-gpmj?

O3 pinpoints whether GHSA-ff24-4prj-gpmj is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-ff24-4prj-gpmj actively exploited in the wild?

No public exploit code has been indexed for GHSA-ff24-4prj-gpmj yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-ff24-4prj-gpmj?

GHSA-ff24-4prj-gpmj has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 46th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-ff24-4prj-gpmj?

GHSA-ff24-4prj-gpmj is classified as Server-Side Request Forgery (SSRF) (CWE-918). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Is there exploit tooling available for GHSA-ff24-4prj-gpmj?

A Nuclei detection template exists for GHSA-ff24-4prj-gpmj, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was GHSA-ff24-4prj-gpmj published, and has it been updated?

GHSA-ff24-4prj-gpmj was published on April 10, 2026 and was last updated on July 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

GHSA-ff24-4prj-gpmj

HIGH

GHSA-ff24-4prj-gpmj is a high-severity (CVSS 7.2) Server-Side Request Forgery (SSRF) vulnerability in github.com/getarcaneapp/arcane/backend. O3 Security confirms whether GHSA-ff24-4prj-gpmj is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Arcane has Unauthenticated SSRF with Conditional Response Reflection in Template Fetch Endpoint

Also known asCVE-2026-40242GO-2026-5356

Published

Apr 10, 2026

Updated

Jul 21, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs46th percentile — riskier than 46% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected

🐹github.com/getarcaneapp/arcane/backend

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Summary

The /api/templates/fetch endpoint accepts a caller-supplied url parameter and performs a server-side HTTP GET request to that URL without authentication and without URL scheme or host validation. The server's response is returned directly to the caller. type. This constitutes an unauthenticated SSRF vulnerability affecting any publicly reachable Arcane instance.

Details

No allowlist or denylist of destination hosts/CIDRs
No requirement for the caller to be authenticated

Response handling produces four distinct outcomes observable by the caller:

Valid JSON targets return a fully reflected response body if the returned fields fit the expected internal struct
Non-JSON HTTP 200 responses produce an error leaking the first byte of the response ("Invalid JSON response: invalid character '<'...")
Non-200 responses leak the HTTP status code
TCP-level failures distinguish between closed ports ("connection refused") and filtered ones ("i/o timeout")

PoC

Send an unauthenticated GET request to /api/templates/fetch, passing the target URL as the url query parameter.

Impact

Unauthenticated port scanning of internal networks
Access to internal HTTP services not exposed to the public internet (service discovery endpoints, internal dashboards, Kubernetes API)

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/getarcaneapp/arcane/backend`	all versions	1.17.3

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/getarcaneapp/arcane/backend. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/getarcaneapp/arcane/backend to 1.17.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-ff24-4prj-gpmj is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-ff24-4prj-gpmj is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-ff24-4prj-gpmj. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary The /api/templates/fetch endpoint accepts a caller-supplied url parameter and performs a server-side HTTP GET request to that URL without authentication and without URL scheme or host validation. The server's response is returned directly to the caller. type. This constitutes an unauthenticated SSRF vulnerability affecting any publicly reachable Arcane instance. ### Details - No allowlist or denylist of destination hosts/CIDRs - No requirement for the caller to be authenticated Response handling produces four distinct outcomes observable by the caller: - Valid JSON targets retur

O3 Security · Impact-Aware SCA

Is GHSA-ff24-4prj-gpmj in your dependencies?

O3 detects GHSA-ff24-4prj-gpmj across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works