{"answers":{"affected":"It affects 2 products.","exploited":"There is no known exploitation of CVE-2018-12891 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2018-12891 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 2 Jul 2018. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2018-12891 and fix it if it is affected.\n\nWhat it is: CVE-2018-12891 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 2 Jul 2018. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2018-12891 in the wild and no public exploit code.\n\nAffected product: Debian Debian Linux. 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-2018-12891/ (Markdown: https://insights.sbomify.com/CVE-2018-12891/index.md)","id":"CVE-2018-12891","markdown":"https://insights.sbomify.com/CVE-2018-12891/index.md","name":"CVE-2018-12891","record":{"aliases":["ALPINE-CVE-2018-12891","DEBIAN-CVE-2018-12891","GHSA-7945-69h3-wr87","UBUNTU-CVE-2018-12891"],"analysis":{"component_type":"operating_system","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Xen hypervisor","requires_auth":"low_privilege","summary":"A malicious multi-vCPU PV guest can cause a host-wide Denial of Service by bypassing preemption checks in Xen hypervisor code paths.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mitre","cpe":[{"product":"debian_linux","vendor":"debian"},{"product":"xen","vendor":"xen"}],"cvss":{"score":6.5,"severity":"medium","source":"nvd","vector":"CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H","version":"3.0"},"cwes":[],"description":"An issue was discovered in Xen through 4.10.x. Certain PV MMU operations may take a long time to process. For that reason Xen explicitly checks for the need to preempt the current vCPU at certain points. A few rarely taken code paths did bypass such checks. By suitably enforcing the conditions through its own page table contents, a malicious guest may cause such bypasses to be used for an unbounded number of iterations. A malicious or buggy PV guest may cause a Denial of Service (DoS) affecting the entire host. Specifically, it may prevent use of a physical CPU for an indeterminate period of time. All Xen versions from 3.4 onwards are vulnerable. Xen versions 3.3 and earlier are vulnerable to an even wider class of attacks, due to them lacking preemption checks altogether in the affected code paths. Only x86 systems are affected. ARM systems are not affected. Only multi-vCPU x86 PV guests can leverage the vulnerability. x86 HVM or PVH guests as well as x86 single-vCPU PV ones cannot leverage the vulnerability.","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":"Denial of service in n/a","id":"CVE-2018-12891","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"debian:debian_linux","products":["debian:debian_linux","xen:xen"],"type":"denial_of_service","year":"2018"},"n_packages":0,"n_references":8,"next":{"headline":"Missing authorization in n/a","id":"CVE-2018-12892"},"packages":[],"prev":{"headline":"Memory corruption in n/a","id":"CVE-2018-12889"},"products":["n/a"],"published":"2018-07-02","related":[{"cvss_score":10,"headline":"ProFTPD Improper Access Control","id":"CVE-2015-3306","kev_date_added":"2026-10-08","published":"2015-05-18"},{"cvss_score":9.9,"headline":"RoundCube Webmail Deserialization of Untrusted Data","id":"CVE-2025-49113","kev_date_added":"2026-02-20","published":"2025-06-02"},{"cvss_score":9.8,"headline":"GNU InetUtils Argument Injection","id":"CVE-2026-24061","kev_date_added":"2026-01-26","published":"2026-01-21"},{"cvss_score":9.8,"headline":"Linux Kernel Improper Check for Unusual or Exceptional Conditions","id":"CVE-2025-39682","kev_date_added":"2026-09-18","published":"2025-09-05"},{"cvss_score":9.8,"headline":"Mozilla Firefox Use-After-Free","id":"CVE-2024-9680","kev_date_added":"2024-10-15","published":"2024-10-09"},{"cvss_score":9.8,"headline":"RARLAB UnRAR Directory Traversal","id":"CVE-2022-30333","kev_date_added":"2022-08-09","published":"2022-05-09"},{"cvss_score":9.8,"headline":"Roundcube Webmail SQL Injection","id":"CVE-2021-44026","kev_date_added":"2023-06-22","published":"2021-11-19"}],"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":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-08-05","vendors":["n/a"]},"summary":"A malicious multi-vCPU PV guest can cause a host-wide Denial of Service by bypassing preemption checks in Xen hypervisor code paths.","url":"https://insights.sbomify.com/CVE-2018-12891/"}