CVE-2026-31970

Published: Mar 18, 2026 Last Modified: Mar 18, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 7,1
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: passive
Confidentiality: N/A
Integrity: N/A
Availability: N/A

Description

AI Translation Available

HTSlib is a library for reading and writing bioinformatics file formats. GZI files are used to index block-compressed GZIP [BGZF] files. In the GZI loading function, `bgzf_index_load_hfile()`, it was possible to trigger an integer overflow, leading to an under- or zero-sized buffer being allocated to store the index. Sixteen zero bytes would then be written to this buffer, and, depending on the result of the overflow the rest of the file may also be loaded into the buffer as well. If the function did attempt to load the data, it would eventually fail due to not reading the expected number of records, and then try to free the overflowed heap buffer. 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. The easiest work-around is to discard any `.gzi` index files from untrusted sources, and use the `bgzip -r` option to recreate them.

122

Heap-based Buffer Overflow

Draft
Abstraction: Variant Structure: Simple
Common Consequences
Security Scopes Affected:
Availability Integrity Confidentiality Access Control Other
Potential Impacts:
Dos: Crash, Exit, Or Restart Dos: Resource Consumption (Cpu) Dos: Resource Consumption (Memory) Execute Unauthorized Code Or Commands Bypass Protection Mechanism Modify Memory Other
Applicable Platforms
Languages: C, C++, Memory-Unsafe
Likelihood of Exploit: High
View CWE Details
131

Incorrect Calculation of Buffer Size

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Availability Confidentiality
Potential Impacts:
Dos: Crash, Exit, Or Restart Execute Unauthorized Code Or Commands Read Memory Modify Memory
Applicable Platforms
Languages: C, C++, Memory-Unsafe
Likelihood of Exploit: High
View CWE Details
190

Integer Overflow or Wraparound

Stable
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Availability Integrity Confidentiality Access Control Other
Potential Impacts:
Dos: Crash, Exit, Or Restart Dos: Resource Consumption (Memory) Dos: Instability Modify Memory Execute Unauthorized Code Or Commands Bypass Protection Mechanism Alter Execution Logic Dos: Resource Consumption (Cpu)
Applicable Platforms
Languages: C, Not Language-Specific
Likelihood of Exploit: Medium
View CWE Details
787

Out-of-bounds Write

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Availability Other
Potential Impacts:
Modify Memory Execute Unauthorized Code Or Commands Dos: Crash, Exit, Or Restart Unexpected State
Applicable Platforms
Languages: Assembly, C, C++, Memory-Unsafe
Technologies: ICS/OT
Likelihood of Exploit: High
View CWE Details
1284

Improper Validation of Specified Quantity in Input

Incomplete
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Other Integrity Availability
Potential Impacts:
Varies By Context Dos: Resource Consumption (Cpu) Modify Memory Read Memory
Applicable Platforms
All platforms may be affected
View CWE Details
https://github.com/samtools/htslib/commit/6dd0d7d0e9e7e2e17…
https://github.com/samtools/htslib/commit/6dd0d7d0e9e7e2e173a28969e624db8bc8bb5…
https://github.com/samtools/htslib/security/advisories/GHSA…
https://github.com/samtools/htslib/security/advisories/GHSA-p345-84hx-fq6q