{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-31966 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2026-31966 is a medium-severity vulnerability in samtools htslib, published on 18 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-31966 and fix it if it is affected.\n\nWhat it is: CVE-2026-31966 is a medium-severity vulnerability in samtools htslib, published on 18 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-31966 in the wild and no public exploit code.\n\nAffected product: samtools htslib. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-31966/ (Markdown: https://insights.sbomify.com/CVE-2026-31966/index.md)","id":"CVE-2026-31966","markdown":"https://insights.sbomify.com/CVE-2026-31966/index.md","name":"CVE-2026-31966","record":{"aliases":["DEBIAN-CVE-2026-31966","GHSA-5cj8-mj52-8vp3","UBUNTU-CVE-2026-31966"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_read","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Bioinformatics file library","requires_auth":"none","summary":"An out-of-bounds read in HTSlib's CRAM decoder allows attackers to leak memory contents or crash the application via crafted files.","user_interaction":"not_required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"htslib","vendor":"htslib"}],"cvss":{"score":6.9,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-129","name":"Improper Validation of Array Index"},{"id":"CWE-125","name":"Out-of-bounds Read"}],"description":"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.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"HTSlib CRAM reader has out-of-bounds read due to improper validation of input","id":"CVE-2026-31966","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"information_disclosure","year":"2026"},"n_packages":0,"n_references":4,"next":{"headline":"HTSlib CRAM reader has out-of-bounds read due to improper validation of input","id":"CVE-2026-31967"},"packages":[],"prev":{"headline":"HTSlib CRAM reader has out-of-bounds reads due to improper validation of input","id":"CVE-2026-31965"},"products":["htslib"],"published":"2026-03-18","related":[{"cvss_score":9.8,"headline":"Memory corruption in n/a","id":"CVE-2018-13845","kev_date_added":null,"published":"2018-07-10"},{"cvss_score":9.8,"headline":"Memory corruption in n/a","id":"CVE-2017-1000206","kev_date_added":null,"published":"2017-11-17"},{"cvss_score":8.8,"headline":"HTSlib CRAM reader has heap buffer overflow due to improper validation of input","id":"CVE-2026-31962","kev_date_added":null,"published":"2026-03-18"},{"cvss_score":8.8,"headline":"HTSlib CRAM reader has heap buffer overflow due to improper validation of input","id":"CVE-2026-31963","kev_date_added":null,"published":"2026-03-18"},{"cvss_score":8.8,"headline":"HTSlib CRAM decoder vulnerable to buffer overflow","id":"CVE-2026-31968","kev_date_added":null,"published":"2026-03-18"},{"cvss_score":8.8,"headline":"Memory corruption in n/a","id":"CVE-2020-36403","kev_date_added":null,"published":"2021-07-01"},{"cvss_score":7.5,"headline":"Denial of service in n/a","id":"CVE-2018-13843","kev_date_added":null,"published":"2018-07-10"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-03-18","vendors":["samtools"]},"summary":"An out-of-bounds read in HTSlib's CRAM decoder allows attackers to leak memory contents or crash the application via crafted files.","url":"https://insights.sbomify.com/CVE-2026-31966/"}