Bug 2561437 (CVE-2026-116742)

Summary: CVE-2026-116742 htslib: htslib: Denial of Service via crafted index file
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: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in HTSlib. A local attacker can cause a Denial of Service (DoS) or memory corruption by convincing a user to process a specially crafted index file. Due to improper integer handling when reading index entry counts, the library performs out-of-bounds heap memory operations, resulting in application crashes.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2565667, 2565668    
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Description OSIDB Bzimport 2026-10-26 22:31:55 UTC 
HTSlib through 1.24 contains a heap out-of-bounds write and read vulnerability in bgzf_index_load_hfile() in bgzf.c that allows attackers to corrupt heap memory by supplying a crafted .gzi index entry count. A count of 0xFFFFFFFF truncates noffs to zero, causing writes past a malloc(0) buffer and an offs[-1] read in bgzf_useek(), resulting in heap corruption or crashes in tools like samtools and bcftools.