{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-117556 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-117556 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-117556 is a medium-severity vulnerability in zchunk, published on 27 Oct 2026."},"fix_prompt":"Check this codebase for CVE-2026-117556 and fix it if it is affected.\n\nWhat it is: CVE-2026-117556 is a medium-severity vulnerability in zchunk, published on 27 Oct 2026. \nExploitation: There is no known exploitation of CVE-2026-117556 in the wild and no public exploit code.\n\nAffected product: zchunk. 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-2026-117556/ (Markdown: https://insights.sbomify.com/CVE-2026-117556/index.md)","id":"CVE-2026-117556","markdown":"https://insights.sbomify.com/CVE-2026-117556/index.md","name":"CVE-2026-117556","record":{"aliases":["AZL-111188","DEBIAN-CVE-2026-117556","GHSA-xcf7-q4j8-4wvv","UBUNTU-CVE-2026-117556"],"analysis":null,"analysis_generated_by":null,"assigner":"VulnCheck","cpe":[],"cvss":{"score":5.3,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-125","name":"Out-of-bounds Read"}],"description":"zchunk before 1.5.5 contains a heap out-of-bounds read vulnerability in read_preface() in src/lib/header.c that passes the total header length instead of remaining bytes to compint parsing functions. Attackers can supply a crafted .zck file whose header ends inside a compressed integer, causing reads past the heap header buffer and crashing the application.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"zchunk before 1.5.5 Heap Out-of-Bounds Read via read_preface()","id":"CVE-2026-117556","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":null,"year":"2026"},"n_packages":0,"n_references":6,"next":{"headline":"SDL_image through 3.4.8 and 2.8.12 Stack Out-of-Bounds Read in ILBM Loader","id":"CVE-2026-117557"},"packages":[],"prev":{"headline":"GreycLab CImg through 4.0.6 Heap Out-of-Bounds Read via Integer Overflow in _load_bmp()","id":"CVE-2026-117555"},"products":["zchunk"],"published":"2026-10-27","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"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":"2026-10-28","vendors":["zchunk"]},"summary":null,"url":"https://insights.sbomify.com/CVE-2026-117556/"}