{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-55781 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-55781 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-55781 is a low-severity denial of service vulnerability in M2Team NanaZip, published on 10 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-55781 and fix it if it is affected.\n\nWhat it is: CVE-2026-55781 is a low-severity denial of service vulnerability in M2Team NanaZip, published on 10 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-55781 in the wild and no public exploit code.\n\nAffected product: M2Team NanaZip. 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-2026-55781/ (Markdown: https://insights.sbomify.com/CVE-2026-55781/index.md)","id":"CVE-2026-55781","markdown":"https://insights.sbomify.com/CVE-2026-55781/index.md","name":"CVE-2026-55781","record":{"aliases":["GHSA-m34h-jf84-m74h"],"analysis":{"component_type":"desktop_application","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Windows archive utility","requires_auth":"low_privilege","summary":"Attackers can cause memory exhaustion and application crash in NanaZip by crafting malicious UFS images with invalid superblock fields.","user_interaction":"required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":2.4,"severity":"low","source":"cna","vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-789","name":"Memory Allocation with Excessive Size Value"},{"id":"CWE-400","name":"Uncontrolled Resource Consumption"}],"description":"NanaZip is the 7-Zip derivative intended for the modern Windows experience. Prior to 6.5.1749.0, NanaZip's UFS and FFS image handler in NanaZip.Codecs.Archive.Ufs.cpp validates the superblock block size only against the MINBSIZE lower bound and does not validate the fs_fsize fragment size, allowing attacker-controlled 32-bit fields to flow into indirect-block, directory, and extraction buffer allocations. A tiny crafted UFS image can force multi-gigabyte allocations during open or extraction, causing memory exhaustion or process termination. This issue is fixed in version 6.5.1749.0.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2026-09-17","github_poc":1,"max_poc_stars":0,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-09-17T00:54:20Z","kind":"github_poc","ref":"https://github.com/NT2DEV/CVE-2026-55781-poc","stars":0,"title":"Unbounded memory allocation in NanaZip's UFS handler via an attacker-controlled `fs_bsize` field."}],"tier":"poc_unverified"},"has_fix":false,"headline":"NanaZip: Unbounded memory allocation (DoS) in NanaZip UFS parser via unvalidated fs_bsize/fs_fsize superblock fields","id":"CVE-2026-55781","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"Denial of service in NanaZip","id":"CVE-2026-55782"},"packages":[],"prev":{"headline":"NanaZip: Uncaught exception / unbounded allocation in NanaZip .NET single-file Extract() via unvalidated entry Size","id":"CVE-2026-55780"},"products":["NanaZip"],"published":"2026-07-10","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)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-07-10","vendors":["M2Team"]},"summary":"Attackers can cause memory exhaustion and application crash in NanaZip by crafting malicious UFS images with invalid superblock fields.","url":"https://insights.sbomify.com/CVE-2026-55781/"}