Bug 2481312 (CVE-2026-8376)

Summary: CVE-2026-8376 perl: Perl: Heap buffer overflow when compiling regular expressions on 32-bit builds
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: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers, yozone
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Perl. A remote attacker could exploit a heap buffer overflow vulnerability when compiling regular expressions with a repeated fixed string on 32-bit builds. Specifically, the `Perl_study_chunk` function in `regcomp_study.c` incorrectly calculates the size of the joined substring buffer, leading to an undersized memory allocation. This allows a subsequent copy operation to write past the end of the buffer, potentially enabling arbitrary code execution or causing a denial of service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2489785    
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Description OSIDB Bzimport 2026-05-26 01:01:19 UTC 
Perl versions through 5.43.10 have a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds.

Perl_study_chunk in regcomp_study.c checked the size of the joined substring buffer in characters rather than bytes. For a quantified fixed substring with a large minimum count, the byte length mincount * l could overflow SSize_t, producing an undersized SvGROW allocation; the subsequent copy writes past the end of the buffer.

A caller that compiles an attacker-controlled regular expression on a 32-bit perl build triggers a heap buffer overflow at compile time.