Apache

CVE-2016-0736: In Apache HTTP Server versions 2.4.0 to 2.4.23, mod_session_crypto was encrypting its data/cookie using the configure…

Is it exploited?

Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of 29 Oct 2026.

VulnCheck KEV lists it since 14 Feb 2023. It cites 1 public report, the first from 14 Feb 2023.

info.securin.io

How likely is exploitation in the next 30 days?

49%

EPSS score, percentile 98.9 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

Not scored

The CVE record carries no CVSS score.

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (7)

Which versions are affected?

Affected

2.4.0 to 2.4.23

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; VulnCheck KEV, as of 30 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 30 Oct 2026. About the data.

Description

In Apache HTTP Server versions 2.4.0 to 2.4.23, mod_session_crypto was encrypting its data/cookie using the configured ciphers with possibly either CBC or ECB modes of operation (AES256-CBC by default), hence no selectable or builtin authenticated encryption. This made it vulnerable to padding oracle attacks, particularly with CBC.

Source: CVE List, as of 30 Oct 2026. About the data.

What to do

Advisories and patches

DSA-3796 (Vendor advisory)
RHSA-2017:1413 (Vendor advisory)
RHSA-2017:1161 (Vendor advisory)
RHSA-2017:1414 (Vendor advisory)
RHSA-2017:1415 (Vendor advisory)
RHSA-2017:0906 (Vendor advisory)
GLSA-201701-36 (Vendor advisory)

This summary is based on the CVE record as of 30 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

Versions by product, as listed in the CVE record (1 product)

Apache Software Foundation Apache HTTP Server
Status	Versions
Affected	2.4.0 to 2.4.23

Source: CVE List, as of 30 Oct 2026. About the data.

Timeline

Date	Event
27 Jul 2017	CVE record published
16 Sep 2024	CVE record last updated

References

40961 (Exploit)
1037508 (Vulnerability database)
95078 (Vulnerability database)
support.apple.com
tenable.com

15 more in the CVE record.

Known exploited Apache vulnerabilities

CVE-2016-3081: Apache Struts Command Injection Vulnerability (added 8 Oct 2026)
CVE-2026-34486: Apache Tomcat Missing Encryption of Sensitive Data Vulnerability (added 4 Aug 2026)
CVE-2026-34197: Apache ActiveMQ Improper Input Validation Vulnerability (added 16 Apr 2026)
CVE-2024-38475: Apache HTTP Server Improper Escaping of Output Vulnerability (added 1 May 2025)
CVE-2025-24813: Apache Tomcat Path Equivalence Vulnerability (added 1 Apr 2025)