CVE-2026-116742

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.

CVSS v3 4.4 MEDIUM

4.4^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 2.5

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/samtools/htslib
https://github.com/samtools/htslib/blob/1.24/bgzf.c#L2504
https://github.com/samtools/htslib/commit/18dddf02bb2c0053b32acec427723555a24b2873
https://github.com/samtools/htslib/issues/2113
https://github.com/samtools/htslib/pull/2057
https://hackmd.io/@haindpwn/htslib-bgzf-gzi-int-truncation-oob
https://www.vulncheck.com/advisories/htslib-through-1.24-heap-out-of-bounds-write-via-truncated-gzi-index-count

Configurations

No configuration.

History

26 Oct 2026, 22:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-26 22:16

Updated : 2026-10-27 16:04

NVD link : CVE-2026-116742

Mitre link : CVE-2026-116742

CVE.ORG link : CVE-2026-116742

JSON object : View

Products Affected

No product.

CWE

CWE-197

Numeric Truncation Error

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