Bug 2571610 (CVE-2026-124738)

Summary: CVE-2026-124738 busybox: httpd password rule bypass for pre-compressed .gz files via Accept-Encoding: gzip
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in BusyBox. When the HTTP daemon (httpd) has pre-compressed file support enabled, authentication checks are evaluated only against the requested URL path rather than the pre-compressed file being served. A remote attacker can exploit this flaw by requesting an uncompressed file path while specifying gzip encoding, bypassing password rules configured specifically for the compressed file. This vulnerability can lead to unauthorized information disclosure of sensitive files.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2571611, 2571612    
Bug Blocks:    

Description OSIDB Bzimport 2026-11-11 09:29:39 UTC 
A flaw was found in BusyBox's httpd. When FEATURE_HTTPD_GZIP is enabled and a request for /FILE includes an Accept-Encoding: gzip header, httpd serves the pre-compressed FILE.gz if it exists, but authentication rules are matched against the request path only. As a result, a password rule configured for /secret.txt.gz can be bypassed by requesting /secret.txt with Accept-Encoding: gzip, disclosing the contents of the protected file. Only rules naming a specific .gz file are affected; directory rules cover both names.