Advisory details:
ubuntu_osv / UBUNTU-CVE-2026-31966
| Advisory ID | ubuntu_osv/UBUNTU-CVE-2026-31966 |
| Aliases |
CVE-2026-31966
|
| Summary | HTSlib is a library for reading and writing bioinformatics file formats. CRAM is a compressed format which stores DNA sequence alignment data. As one method of removing redundant data, CRAM uses reference-based compression so that instead of storing the full sequence for each alignment record it stores a location in an external reference sequence along with a list of differences to the reference at that location as a sequence of "features". When decoding CRAM records, the reference data is stored in a char array, and parts matching the alignment record sequence are copied over as necessary. Due to insufficient validation of the feature data series, it was possible to make the `cram_decode_seq()` function copy data from either before the start, or after the end of the stored reference either into the buffer used to store the output sequence for the cram record, or into the buffer used to build the SAM `MD` tag. This allowed arbitrary data to be leaked to the calling function. This bug may allow information about program state to be leaked. It may also cause a program crash through an attempt to access invalid memory. Versions 1.23.1, 1.22.2 and 1.21.1 include fixes for this issue. There is no workaround for this issue. |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 8.2 |
| Risk | 4.1 |
| Affected and Fixed Packages | Package Details |
| Introduced and Fixed Package Commit Patches | Package Commit Patches Details |
| There are no known CWE. |
| Reference id | Reference type | URL |
|---|---|---|
| https://ubuntu.com/security/CVE-2026-31966 | ||
| https://www.cve.org/CVERecord?id=CVE-2026-31966 | ||
| 22ec5230ef95769ab009420da69568c7e530af28 | Other | https://github.com/samtools/htslib/commit/22ec5230ef95769ab009420da69568c7e530af28 |
| 2a45eb129d703ad27f9fabc8169f0e94d3c69fa3 | Other | https://github.com/samtools/htslib/commit/2a45eb129d703ad27f9fabc8169f0e94d3c69fa3 |
| 4a5ef25eb1fb3d64438103316fffe423b2c3f5f4 | Other | https://github.com/samtools/htslib/commit/4a5ef25eb1fb3d64438103316fffe423b2c3f5f4 |
| GHSA-5cj8-mj52-8vp3 | Other | https://github.com/samtools/htslib/security/advisories/GHSA-5cj8-mj52-8vp3 |
No EPSS data available for this advisory.
| Patch URL | |
|---|---|
| There are no known patches. | |
| Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
|---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
| Attack Vector (AV) | Attack Complexity (AC) | Attack Requirements (AT) | Privileges Required (PR) | User Interaction (UI) | Vulnerable System Impact Confidentiality (VC) | Vulnerable System Impact Integrity (VI) | Vulnerable System Impact Availability (VA) | Subsequent System Impact Confidentiality (SC) | Subsequent System Impact Integrity (SI) | Subsequent System Impact Availability (SA) |
|---|---|---|---|---|---|---|---|---|---|---|
network adjacent local physical |
low high |
none present |
none low high |
none passive active |
high low none |
high low none |
high low none |
high low none |
high low none |
high low none |
There are no SSVC decisions available.