CVE-2026-31964 | samtools htslib up to 1.21.0/1.22.1/1.23 null pointer dereference

VDB-351598 · CVE-2026-31964 · GCVE-0-2026-31964 SAMTOOLS HTSLIB UP TO 1.21.0/1.22.1/1.23 NULL POINTER DEREFERENCE HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 6.2 $0-$5k 0.35+ Summaryinfo A vulnerability, which was classified as problematic, was found in samtools htslib up to 1.21.0/1.22.1/1.23. Impacted is an unknown function. Executing a manipulation can lead to null pointer dereference. This vulnerability appears as CVE-2026-31964. The attack may be performed from remote. There is no available exploit. You should upgrade the affected component. Detailsinfo A vulnerability has been found in samtools htslib up to 1.21.0/1.22.1/1.23 and classified as critical. This vulnerability affects some unknown functionality. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect integrity, and availability. CVE summarizes: 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. While most alignment records store DNA sequence and quality values, the format also allows them to omit this data in certain cases to save space. Due to some quirks of the CRAM format, it is necessary to handle these records carefully as they will actually store data that needs to be consumed and then discarded. Unfortunately the `CONST`, `XPACK` and `XRLE` encodings did not properly implement the interface needed to do this. Trying to decode records with omitted sequence or quality data using these encodings would result in an attempt to write to a NULL pointer. 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 advisory is available at github.com. This vulnerability was named CVE-2026-31964 since 03/10/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. The technical details are unknown and an exploit is not available. Upgrading to version 1.21.1 or 1.22.2 eliminates this vulnerability. Productinfo Vendor samtools Name htslib Version 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.21.0 1.22 1.22.0 1.22.1 1.23 Website Product: https://github.com/samtools/htslib/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA CVSS-B Score: 🔒 CNA CVSS-BT Score: 🔒 CNA Vector: 🔒 CVSSv3info VulDB Meta Base Score: 6.5 VulDB Meta Temp Score: 6.2 VulDB Base Score: 6.5 VulDB Temp Score: 6.2 VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Null pointer dereference CWE: CWE-476 / CWE-404 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: htslib 1.21.1/1.22.2 Timelineinfo 03/10/2026 CVE reserved 03/18/2026 +8 days Advisory disclosed 03/18/2026 +0 days VulDB entry created 03/18/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: github.com Status: Confirmed CVE: CVE-2026-31964 (🔒) GCVE (CVE): GCVE-0-2026-31964 GCVE (VulDB): GCVE-100-351598 Entryinfo Created: 03/18/2026 20:02 Changes: 03/18/2026 20:02 (66) Complete: 🔍 Cache ID: 99:248:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸