{"cve":"CVE-2026-31968","nvd":{"published":"2026-03-18T20:16:21.480","modified":"2026-06-17T10:34:51.650","status":"Analyzed","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_v4":{"vector":"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","score":8.8},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H","score":8.1},"cwes":["CWE-121","CWE-122","CWE-787","CWE-843"],"references":["https://github.com/samtools/htslib/commit/0ec436796eca7b4ce7fcc9b77270c102da29bb2e","https://github.com/samtools/htslib/security/advisories/GHSA-cgcm-c9r2-p57j"],"products":["htslib:htslib"],"source":"nvd","synced_at":"2026-10-19T22:26:19.218427112+00:00"},"epss":{"cve":"CVE-2026-31968","score":0.00425,"percentile":0.36777,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}