Vulnerability Description
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 Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/samtools/htslib
- https://github.com/samtools/htslib/blob/1.24/bgzf.c#L2504
- https://github.com/samtools/htslib/commit/18dddf02bb2c0053b32acec427723555a24b28
- 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-writ
FAQ
What is CVE-2026-116742?
CVE-2026-116742 is a vulnerability with a CVSS score of 4.4 (MEDIUM). 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...
How severe is CVE-2026-116742?
CVE-2026-116742 has been rated MEDIUM with a CVSS base score of 4.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-116742?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.