# CVE-2026-103043 — alexcorvi anchorme

> As of 2026-09-30, CVE-2026-103043 is a HIGH-severity vulnerability in alexcorvi anchorme, CVSS v3.1 7.5. No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-103043 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-2026-103043?

anchorme through 3.0.8 contains a regular expression denial of service vulnerability in the IPv6 host extraction regex due to catastrophic backtracking. Attackers can supply specially crafted input strings with repeated patterns to cause exponential regex engine backtracking, blocking the Node.js event loop and denying service to other requests.

The record classifies CVE-2026-103043 under weakness class [CWE-1333](https://cwe.mitre.org/data/definitions/1333.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 6 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.5 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **CVSS v4.0 base score:** 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-09-29, last modified 2026-09-30

## Is CVE-2026-103043 being exploited?

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

## Affected products and versions

- **alexcorvi**: anchorme

## How to fix CVE-2026-103043

No vendor patch reference has been recorded for CVE-2026-103043 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-2026-103043

No threat campaign in the Threadlinqs corpus currently references CVE-2026-103043, 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, NVD, GitHub Security Advisories. Last verified by Threadlinqs on 2026-09-30. This product uses the NVD API but is not endorsed or certified by the NVD.

**Technical analysis**

- [github.com — technical description](https://github.com/alexcorvi/anchorme.js/blob/f3ae9850baa344f27b46bb149e9b891831d273b1/src/index.ts#L109)

**Third-party advisory**

- [gist.github.com — third party advisory](https://gist.github.com/mmadersbacher/46050b4224eb979431986cdef1dd2ad3)
- [vulncheck.com — third party advisory](https://www.vulncheck.com/advisories/anchorme-through-3.0.8-regular-expression-denial-of-service)

**Issue tracking and product pages**

- [npmjs.com — product](https://www.npmjs.com/package/anchorme)
- [github.com — product](https://github.com/alexcorvi/anchorme.js)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-103043
Full detection coverage and IOCs for threats exploiting CVE-2026-103043 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp