CVE-2026-56154 Apache HTTP Server - Use After Free

Apache HTTP Server 2.4.0 through 2.4.68 contains a use after free vulnerability caused by improper handling of lookahead (%{LA-U:HTTP:...}) in mod_rewrite, letting attackers cause denial of service or potentially execute code, exploit requires crafted requests.

CVSS base score 9.8 /10
Critical
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.56% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Use After Free
Impact
Denial Of Service, Remote Code Execution
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
1 October 2026
Updated
15 October 2026
Weakness
CWE-416

Vendor fix

Upgrade to a version later than 2.4.68 or the latest available version.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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