High Authentication

CVE-2026-73636 — Authentication Bypass by Capture-replay in Apache Software Foundation Apache HTTP Server

Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0. Users are recommended to upgrade to version 2.4.69, which fixes this issue.

Published Oct 1, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database · CNA: security@apache.org

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

—

No EPSS score.

Affects

Apache Software Foundation

Apache HTTP Server

CVSS base

8.1

High · 1 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Apache Software Foundation Apache HTTP Server).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Apache Software Foundation	Apache HTTP Server	≥ 2.4.0 and < 2.4.69	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

High

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.1	CVSS 3.1	High	2.2	5.9	134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 134c704f-9b21-4f2e-91b3-4a467353bcc0)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-294 · Authentication Bypass by Capture-replay

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.

web/proxy/WAF logsnetwork IDS/IPSauthentication logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 15, 2026
CVSS changed · 8.1
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Oct 1, 2026 · security@apache.org

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

2 on the record

httpd.apache.org/security/vulnerabilities_24.html
Vendor Advisory, NIST National Vulnerability Database
www.openwall.com/lists/oss-security/2026/10/01/27
Mailing List, Third Party Advisory, NIST National Vulnerability Database

Elsewhere on this site

Apache Software Foundation
every CVE for this vendor

Authentication
same class

CWE-294
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-93546 Integer Overflow or Wraparound in Apache Software Foundation Apache HTTP Server 14d
Medium CVE-2026-79768 Path equivalence: '/./' (single dot directory) vulnerability in Apache HTTP Server's… 14d
High CVE-2026-73637 Use After Free in Apache Software Foundation Apache HTTP Server 14d
High CVE-2026-63718 Apache HTTP Server: mod_proxy_uwsgi Transfer-Encoding response smuggling 14d
High CVE-2026-63045 Improper Access Control in Apache Software Foundation Apache HTTP Server 14d
High CVE-2026-59685 Out-of-bounds Write in Apache Software Foundation Apache HTTP Server 14d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No FIRST EPSS score.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-73636 is "Authentication Bypass by Capture-replay in Apache Software Foundation Apache HTTP Server", rated High. It affects Apache HTTP Server (Apache Software Foundation); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.1 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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