{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-84971 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2026-84971 is a high-severity denial of service vulnerability in MongoDB libmongocrypt, published on 3 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-84971 and fix it if it is affected.\n\nWhat it is: CVE-2026-84971 is a high-severity denial of service vulnerability in MongoDB libmongocrypt, published on 3 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-84971 in the wild and no public exploit code.\n\nAffected product: MongoDB libmongocrypt. 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-2026-84971/ (Markdown: https://insights.sbomify.com/CVE-2026-84971/index.md)","id":"CVE-2026-84971","markdown":"https://insights.sbomify.com/CVE-2026-84971/index.md","name":"CVE-2026-84971","record":{"aliases":["DEBIAN-CVE-2026-84971","GHSA-pxxc-vwf4-r3mr","UBUNTU-CVE-2026-84971"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"MongoDB client encryption library","requires_auth":"low_privilege","summary":"An attacker can cause a denial of service by triggering a crash in the MongoDB client encryption library via malformed ciphertext.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mongodb","cpe":[{"product":"libmongocrypt","vendor":"mongodb"}],"cvss":{"score":7.1,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-617","name":"Reachable Assertion"}],"description":"Improper handling of an unexpected value size in the decryption path of a client-side encryption library can cause a failed internal check that terminates the process using the library. A party able to place a suitably formed encrypted value where an application will decrypt it, or able to control the responses the application receives, may cause that application to stop running.","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":"Persistent client crash loop via undersized FLE2 insert-update ciphertext in decryption path","id":"CVE-2026-84971","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":1,"next":{"headline":"Security feature bypass in pjproject","id":"CVE-2026-84975"},"packages":[],"prev":{"headline":"Heap over-read or silent misparse via 32-bit truncation of JSON length in BSON JSON parser","id":"CVE-2026-84970"},"products":["libmongocrypt"],"published":"2026-09-03","related":[{"cvss_score":8.7,"headline":"Heap corruption via duplicate masterKey fields in MongoDB libmongocrypt","id":"CVE-2026-106433","kev_date_added":null,"published":"2026-10-08"},{"cvss_score":5.7,"headline":"Authenticated KMS request forgery via CRLF injection in GCP key identifier strings","id":"CVE-2026-84962","kev_date_added":null,"published":"2026-09-03"},{"cvss_score":2,"headline":"Cross-tenant database retargeting via dot/NUL injection in namespace strings in libmongocrypt","id":"CVE-2026-81523","kev_date_added":null,"published":"2026-08-27"}],"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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-09-03","vendors":["MongoDB"]},"summary":"An attacker can cause a denial of service by triggering a crash in the MongoDB client encryption library via malformed ciphertext.","url":"https://insights.sbomify.com/CVE-2026-84971/"}