# CVE-2026-103592 — pecee simple-router

> As of 2026-09-30, CVE-2026-103592 is a MEDIUM-severity vulnerability in pecee simple-router, CVSS v3.1 6.5. No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-103592 as of 2026-09-30; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-09-30

## What is CVE-2026-103592?

simple-php-router through 5.4.1.7 contains an IP restriction bypass vulnerability in the IpRestrictAccess middleware that allows remote unauthenticated attackers to bypass IP whitelist and blacklist protections. Attackers can spoof X-Forwarded-For, CF-Connecting-IP, or Client-IP headers to impersonate whitelisted addresses or evade blacklists, gaining access to IP-restricted routes.

The record classifies CVE-2026-103592 under weakness class [CWE-348](https://cwe.mitre.org/data/definitions/348.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 5 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 6.5 — MEDIUM (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **CVSS v4.0 base score:** 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-09-30

## Is CVE-2026-103592 being exploited?

It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **pecee**: simple-router

## How to fix CVE-2026-103592

No vendor patch reference has been recorded for CVE-2026-103592 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-103592

No threat campaign in the Threadlinqs corpus currently references CVE-2026-103592, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, GitHub Security Advisories. Last verified by Threadlinqs on 2026-10-01.

**Technical analysis**

- [github.com — technical description](https://github.com/skipperbent/simple-php-router/blob/5.4.1.7/src/Pecee/Http/Middleware/IpRestrictAccess.php)
- [github.com — technical description (Request)](https://github.com/skipperbent/simple-php-router/blob/5.4.1.7/src/Pecee/Http/Request.php)

**Third-party advisory**

- [vulncheck.com — third party advisory](https://www.vulncheck.com/advisories/simple-php-router-through-5.4.1.7-ip-restriction-bypass-via-forwarding-headers)

**Issue tracking and product pages**

- [github.com — issue tracking](https://github.com/skipperbent/simple-php-router/issues/727)
- [github.com — product](https://github.com/skipperbent/simple-php-router)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-103592
Full detection coverage and IOCs for threats exploiting CVE-2026-103592 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp