How severe is CVE-2026-58497?

No CVSS score has been assigned to CVE-2026-58497 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-58497?

CVE-2026-58497 affects the following packages: @zenalexa/unicli (npm). Ecosystems affected: npm.

How do I fix CVE-2026-58497?

Update @zenalexa/unicli to 0.225.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-58497 is resolved across your whole dependency graph.

How do I detect CVE-2026-58497 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @zenalexa/unicli, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-58497 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.

Is CVE-2026-58497 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-58497 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 CVE-2026-58497?

CVE-2026-58497 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 17th 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 CVE-2026-58497?

CVE-2026-58497 is classified as CWE-346 (CWE-346), Cross-Site Request Forgery (CSRF) (CWE-352). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-58497 published, and has it been updated?

CVE-2026-58497 was published on October 23, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

CVE-2026-58497 — @zenalexa/unicli

CVE-2026-58497 is a CWE-346 vulnerability in @zenalexa/unicli. A fix is available for @zenalexa/unicli — see the affected versions and patch details below.

Uni-CLI: Legacy HTTP MCP transport accepted browser-originated localhost requests

Also known asGHSA-v3f4-w7r7-v3hm

Published

Oct 23, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 31, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-58497.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs17th percentile — riskier than 17% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

0other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@zenalexa/uniclinpm

282downloads / week

Description

Impact

Uni-CLI versions before 0.225.2 exposed the legacy JSON-RPC-over-HTTP MCP transport on loopback without validating browser Origin headers before routing requests. A malicious web page could send a CORS simple POST request, such as text/plain, to the local /mcp endpoint and deliver a JSON-RPC body to the dispatcher. If the user had started the local MCP HTTP transport, that page could drive tools/call requests against the user's local Uni-CLI server.

The Streamable HTTP transport already enforced this browser-to-localhost boundary. The legacy stateless HTTP path did not, so the two HTTP transports had drifted. This issue is about the browser-to-localhost boundary; it does not change Uni-CLI's local-code-execution trust model.

Patches

Version 0.225.2 fixes the issue by moving the Origin policy into a shared guard and applying it before routing in both HTTP transports. Non-loopback browser Origins are rejected with HTTP 403 before health, OAuth, or /mcp dispatch runs. Non-browser clients that omit Origin remain supported.

Workarounds

Upgrade to 0.225.2 or later. If upgrading is not immediately possible, do not expose the legacy HTTP MCP transport to browser-originated traffic; use the default stdio transport or the Streamable HTTP transport instead.

Credits

Reported privately by Ryan Vonbrubeck (@dodge1218).

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@zenalexa/unicli`	all versions	0.225.2`npm install @zenalexa/unicli@0.225.2`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @zenalexa/unicli, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @zenalexa/unicli to 0.225.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-58497 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.

Frequently Asked Questions

## Impact Uni-CLI versions before 0.225.2 exposed the legacy JSON-RPC-over-HTTP MCP transport on loopback without validating browser Origin headers before routing requests. A malicious web page could send a CORS simple POST request, such as text/plain, to the local /mcp endpoint and deliver a JSON-RPC body to the dispatcher. If the user had started the local MCP HTTP transport, that page could drive tools/call requests against the user's local Uni-CLI server. The Streamable HTTP transport already enforced this browser-to-localhost boundary. The legacy stateless HTTP path did not, so the two

O3 Security · Impact-Aware SCA

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CVE-2026-58497 — @zenalexa/unicli

Exploitation Status

No confirmed exploitation observed yet

EPSS Exploitation Probability

Real-World Exposure

Description

Impact

Patches

Workarounds

Credits

Affected Packages

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2026-58497 in your dependencies?