CVE-2026-56154Hinoki check available

Unspecified impact via HTTP-header lookahead use-after-free

Published Oct 1, 2026 · Updated Oct 1, 2026

Use-after-free in mod_rewrite in Apache HTTP Server 2.4.0 through 2.4.68 exposes servers using URL lookahead to unspecified impact. The affected %{LA-U:HTTP:...} expression performs an internal subrequest to read an HTTP header, but Apache has not disclosed the exact memory-lifetime error. Reachability requires an enabled rewrite rule that evaluates this expression; Apache has not specified whether the error crashes a worker or has another consequence.

CVSS severityUnavailable
Unscored
EPSS probability0.56%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Use-after-free in mod_rewrite in Apache HTTP Server 2.4.0 through 2.4.68 exposes servers using URL lookahead to unspecified impact. The affected %{LA-U:HTTP:...} expression performs an internal subrequest to read an HTTP header, but Apache has not disclosed the exact memory-lifetime error. Reachability requires an enabled rewrite rule that evaluates this expression; Apache has not specified whether the error crashes a worker or has another consequence.

The record

CVE
CVE-2026-56154
Published
Oct 1, 2026
Updated
Oct 1, 2026
Vendor
The Apache Software Foundation
Product
Apache HTTP Server
Classifications
CWE-416
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=2.4.0 <=2.4.68

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Apache Software Foundation · Apache HTTP Serverversion=2.4.0 <=2.4.68

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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