Heap Buffer Overflow in HTSlib Affects Bioinformatics Data Processing
CVE-2026-31963

8.8HIGH

Key Information:

Vendor

Samtools

Status
Htslib
Vendor
CVE Published:
18 March 2026

What is CVE-2026-31963?

HTSlib, a library designed for reading and writing bioinformatics file formats, is susceptible to a heap buffer overflow. This vulnerability arises when handling CRAM, a compressed format used to store DNA sequence alignment data. An out-by-one error in the decoding process allows attacker-controlled input to exploit a buffer, potentially leading to program crashes and unexpected manipulation of data structures. If successfully exploited, this flaw can result in arbitrary code execution, emphasizing the importance of upgrading to patched versions 1.23.1, 1.22.2, or 1.21.1 to mitigate risks.

Affected Version(s)

htslib < 1.21.1 < 1.21.1

htslib >= 1.22, < 1.22.2 < 1.22, 1.22.2

htslib = 1.23 = 1.23

References

https://github.com/samtools/htslib/security/advisories/GH...
x_refsource_CONFIRM
https://github.com/samtools/htslib/commit/8bcc9907be0f945...
x_refsource_MISC

CVSS V4

Score:
8.8
Severity:
HIGH
Confidentiality:
None
Integrity:
High
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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