CVE-2026-31973CWE-476

NULL pointer dereference in samtools cram-size

Medium · published March 18, 2026

CVSS v4.0
6.9
EPSS
1%
Percentile
50.0
In the wild
Unconfirmed
What it is

SAMtools is a program for reading, manipulating and writing bioinformatics file formats. Starting in version 1.17, in the cram-size command, used to write information about how well CRAM files are compressed, a check to see if the `cram_decode_compression_header()` was missing. If the function returned an error, this could lead to a NULL pointer dereference. Exploiting this bug causes a NULL pointer dereference. Typically this will cause the program to crash. Versions 1.23.1, 1.22.2 and 1.21.1 include fixes for this issue. There is no workaround for this issue.

The record
Technical detail
CVSS v4.0
6.9 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
EPSS
0.00640 · 50.0th percentile
Weakness
CWE-476 · NULL Pointer Dereference
Published
2026-03-18T20:34Z
EPSS history
Timeline
  • 18 MAR 20:34Z
    NULL pointer dereference in samtools cram-size
    cvelistv5