Worker crash via stale language-array pointer
Published Jun 8, 2026 · Updated Jun 8, 2026
Out-of-bounds reads in Apache HTTP Server 2.4.0 through 2.4.67 allow remote attackers to crash workers by requesting multilingual content. The response-header loop appends unseen Content-Language tokens to content_languages, which can reallocate the array, but pre-fix code reuses an element pointer captured before iteration. Exploitation requires mod_headers, mod_mime and multiple response languages; the reported consequence is worker interruption, not arbitrary code execution.
Summary
What happened
Out-of-bounds reads in Apache HTTP Server 2.4.0 through 2.4.67 allow remote attackers to crash workers by requesting multilingual content. The response-header loop appends unseen Content-Language tokens to content_languages, which can reallocate the array, but pre-fix code reuses an element pointer captured before iteration. Exploitation requires mod_headers, mod_mime and multiple response languages; the reported consequence is worker interruption, not arbitrary code execution.
The record
- CVE
- CVE-2026-43951
- Published
- Jun 8, 2026
- Updated
- Jun 8, 2026
- Vendor
- The Apache Software Foundation
- Product
- Apache HTTP Server
- Classifications
- CWE-125, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 8, 2026CVE publishedPublication date reported by the CVE source.
- Jun 8, 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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- Affected versionversion=2.4.0 <=2.4.67
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
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Your stack
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