Vulnerability · CVE-2026-31969
HTSlib is a library for reading and writing bioinformatics file formats.
Published Mar 18, 2026 · catalog updated Jun 17, 2026 · HTSlib is a library
Check if you run it
No confirmed exploitation is on record for CVE-2026-31969. EPSS is 0.54%. Act only if a listed version of HTSlib is a library is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (HTSlib is a library).
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- High7.1
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.54%
- Remediation
- Advisory link
- Affected products
- cpe htslib/htslib
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 method, an out-by-one error in the 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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe htslib/htslib1.23
How to fix CVE-2026-31969
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-31969. EPSS is 0.54%. Act only if a listed version of HTSlib is a library is installed.
Which versions are affected?
Compare what you have installed with 1.23. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-122: Heap-based Buffer Overflow; CWE-787: Out-of-bounds Write. EPSS 0.54%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Mar 18, 2026 · NIST NVD
Detected
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 method, an out-by-one error in the function check for a full output buffer could result in a single attacker-controlled byte being written beyond the end of a heap allo
Jun 17, 2026 · NIST NVD
Updated
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 method, an out-by-one error in the function check for a full output buffer could result in a single attacker-controlled byte being written beyond the end of a heap allo
Sources
- CVE.orgVulnerability recordCVE-2026-31969
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-31969
30-day exploitation probability 0.5%
first.org - NIST NVDVulnerability recordCVE-2026-31969
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 method, an out-by-one error i
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.