CVE-2026-31968

HIGH EPSS 32.7%
Published Mar 18, 20263mo ago · Modified Mar 19, 20263mo ago
8.8 CVSS 4.0
High
Find Similar
Published Mar 18, 2026 3mo ago
Last Modified Mar 19, 2026 3mo ago

Description

HTSlib is a library for reading and writing bioinformatics file formats. CRAM is a compressed format which stores DNA sequence alignment data using a variety of encodings and compression methods. For the `VARINT` and `CONST` encodings, incomplete validation of the context in which the encodings were used could result in up to eight bytes being written beyond the end of a heap allocation, or up to eight bytes being written to the location of a one byte variable on the stack, possibly causing the values to adjacent variables to change unexpectedly. Depending on the data stream this could result either in a heap buffer overflow or a stack overflow. If a user opens a file crafted to exploit this issue it could lead to the program crashing, overwriting of data structures on the heap or stack in ways not expected by the program, or changing the control flow of the program. It may be possible to use this to obtain arbitrary code execution. Versions 1.23.1, 1.22.2 and 1.21.1 include fixes for this issue. There is no workaround for this issue.

CVSS Details

Base Score
8.8
Exploitability
Impact
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
32.7% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 4

CWE-121
CWE-122
CWE-787 Out-of-bounds Write Memory Safety
CWE-843

Affected Products 3

VendorProductVersionRange
htslibhtslib* <1.21.1
htslibhtslib*≥1.22  –  <1.22.2
htslibhtslib1.23any

References 2

  • github.com https://github.com/samtools/htslib/commit/0ec436796eca7b4ce7fcc9b77270c102da29bb2e
    Patch
  • github.com https://github.com/samtools/htslib/security/advisories/GHSA-cgcm-c9r2-p57j
    PatchVendor Advisory

Remediation

  • github.com https://github.com/samtools/htslib/commit/0ec436796eca7b4ce7fcc9b77270c102da29bb2e
    Patch
  • github.com https://github.com/samtools/htslib/security/advisories/GHSA-cgcm-c9r2-p57j
    PatchVendor Advisory