{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-81634 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2026-81634 is a high-severity memory corruption vulnerability in Nlnetlabs Unbound, published on 16 Sep 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-2026-81634 and fix it if it is affected.\n\nWhat it is: CVE-2026-81634 is a high-severity memory corruption vulnerability in Nlnetlabs Unbound, published on 16 Sep 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-2026-81634 in the wild and no public exploit code.\n\nAffected product: Nlnetlabs Unbound. 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-2026-81634/ (Markdown: https://insights.sbomify.com/CVE-2026-81634/index.md)","id":"CVE-2026-81634","markdown":"https://insights.sbomify.com/CVE-2026-81634/index.md","name":"CVE-2026-81634","record":{"aliases":["AZL-101721","DEBIAN-CVE-2026-81634","ECHO-258d-90d7-a305","GHSA-x9ff-rj4v-x6mq","ROOT-OS-DEBIAN-12-CVE-2026-81634","UBUNTU-CVE-2026-81634"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["code_execution","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"DNS resolver","requires_auth":"none","summary":"A heap buffer overflow in Unbound allows remote attackers to execute code or cause denial of service via malicious DNS responses.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"NLnet Labs","cpe":[{"product":"unbound","vendor":"nlnetlabs"}],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-122","name":"Heap-based Buffer Overflow"}],"description":"In NLnet Labs Unbound up to and including 1.26.0, a 255 length query name with a large TCP response can lead to a heap buffer overflow during the RRSet canonicalisation routine. This is caused by missing to add the first owner name into the buffer length check. A malicious actor operating a malicious name server or tampering with an incoming response to Unbound (canonicalisation happens before DNSSEC validation), can trigger 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":"Possible heap buffer overflow during DNSSEC canonicalization","id":"CVE-2026-81634","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"nlnetlabs:unbound","products":["nlnetlabs:unbound"],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":1,"next":{"headline":"Cross-site scripting in SHIRASAGI","id":"CVE-2026-81635"},"packages":[],"prev":{"headline":"Unhandled KeyError in AshGraphql relay node resolution crashes queries via an unknown type segment","id":"CVE-2026-81633"},"products":["Unbound"],"published":"2026-09-16","related":[{"cvss_score":9.1,"headline":"Heap buffer overflow and possible Remote Code Execution when digesting DNSKEY","id":"CVE-2026-81642","kev_date_added":null,"published":"2026-09-16"},{"cvss_score":9.1,"headline":"Possible arbitrary code execution during DNSSEC validation","id":"CVE-2026-33278","kev_date_added":null,"published":"2026-05-20"},{"cvss_score":8.7,"headline":"Heap overflow with multiple NSID, COOKIE, PADDING EDNS options","id":"CVE-2026-42944","kev_date_added":null,"published":"2026-05-20"},{"cvss_score":8.7,"headline":"Crash during DNSSEC validation of malicious content","id":"CVE-2026-42959","kev_date_added":null,"published":"2026-05-20"},{"cvss_score":8.4,"headline":"CNAME synthesis could lead to heap corruption","id":"CVE-2026-82717","kev_date_added":null,"published":"2026-09-16"},{"cvss_score":7.5,"headline":"Remote DNS-over-QUIC denial of service due to `quic-size` budget bypass","id":"CVE-2026-32665","kev_date_added":null,"published":"2026-07-22"}],"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":"2026-09-16","vendors":["NLnet Labs"]},"summary":"A heap buffer overflow in Unbound allows remote attackers to execute code or cause denial of service via malicious DNS responses.","url":"https://insights.sbomify.com/CVE-2026-81634/"}