CVE-2026-31969

HIGH EPSS 25.4%
Published Mar 18, 20263mo ago · Modified Mar 19, 20263mo ago
7.1 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. When reading data encoded using the `BYTE_ARRAY_STOP` method, an out-by-one error in the `cram_byte_array_stop_decode_char()` function check for a full output buffer could result in a single attacker-controlled byte being written beyond the end of a heap allocation. Exploiting this bug causes a heap buffer overflow. If a user opens a file crafted to exploit this issue, it could lead to the program crashing, or overwriting of data and heap structures in ways not expected by 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
7.1
Exploitability
Impact
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/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 P
Scope X

Threat Intelligence

EPSS Exploit Probability
25.4% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 2

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

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/88cdf69e4b83bb550ab4f6f7134892c2ad1978f4
    Patch
  • github.com https://github.com/samtools/htslib/security/advisories/GHSA-q4cj-f4h5-fqgc
    PatchVendor Advisory

Remediation

  • github.com https://github.com/samtools/htslib/commit/88cdf69e4b83bb550ab4f6f7134892c2ad1978f4
    Patch
  • github.com https://github.com/samtools/htslib/security/advisories/GHSA-q4cj-f4h5-fqgc
    PatchVendor Advisory