# CVE-2026-73637 — Apache HTTP Server

> As of 2026-10-01, CVE-2026-73637 is a HIGH-severity vulnerability in Apache HTTP Server, CVSS v3.1 7.3, EPSS 0.4% (39.7th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-73637, most recently “Multiple Vulnerabilities in Apache HTTP Server 2.4.0 through 2.4.68 (20 CVEs, fixed in 2.4.69)”.

**Last updated:** 2026-10-01

## What is CVE-2026-73637?

Use after free in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an unauthenticated remote client to cause authentication state corruption via concurrent Digest authentication requests when AuthDigestNcCheck is enabled or AuthDigestNonceLifetime is set to 0. Users are recommended to upgrade to version 2.4.69, which fixes this issue.

The record classifies CVE-2026-73637 under weakness class [CWE-416](https://intel.threadlinqs.com/cwe/CWE-416). 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 22 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.3 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L`)
- **EPSS (FIRST):** 0.4% probability of exploitation in the next 30 days, higher than 39.7% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 5.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-10-01

## Is CVE-2026-73637 being exploited?

It currently carries a trending score of 43 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Apache Software Foundation](https://intel.threadlinqs.com/vendors/apache-software-foundation): Apache HTTP Server

## How to fix CVE-2026-73637

Vendor advisory: [https://httpd.apache.org/security/vulnerabilities_24.html](https://httpd.apache.org/security/vulnerabilities_24.html). Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

## Threat activity tracking CVE-2026-73637

1 tracked threat in the Threadlinqs corpus references CVE-2026-73637, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Multiple Vulnerabilities in Apache HTTP Server 2.4.0 through 2.4.68 (20 CVEs, fixed in 2.4.69)](https://intel.threadlinqs.com/threat/TL-2026-2876) — MEDIUM · 2026-10-02

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-10-10. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [httpd.apache.org — vendor advisory](https://httpd.apache.org/security/vulnerabilities_24.html)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-73637
Full detection coverage and IOCs for threats exploiting CVE-2026-73637 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp