{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-66199 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2025-66199 is a medium-severity vulnerability in Openssl Openssl, published on 27 Jan 2026."},"fix_prompt":"Check this codebase for CVE-2025-66199 and fix it if it is affected.\n\nWhat it is: CVE-2025-66199 is a medium-severity vulnerability in Openssl Openssl, published on 27 Jan 2026. \nExploitation: There is no known exploitation of CVE-2025-66199 in the wild and no public exploit code.\n\nAffected product: Openssl Openssl. 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-2025-66199/ (Markdown: https://insights.sbomify.com/CVE-2025-66199/index.md)","id":"CVE-2025-66199","markdown":"https://insights.sbomify.com/CVE-2025-66199/index.md","name":"CVE-2025-66199","record":{"aliases":["ALPINE-CVE-2025-66199","AZL-75284","BELL-CVE-2025-66199","CLSA-2026-1772112014","DEBIAN-CVE-2025-66199","GHSA-5888-36j9-c92p","JLSEC-2026-260","MINI-2vpp-59xh-28xc","MINI-mgc9-4rpq-57xp","UBUNTU-CVE-2025-66199"],"analysis":null,"analysis_generated_by":null,"assigner":"openssl","cpe":[{"product":"openssl","vendor":"openssl"}],"cvss":{"score":5.9,"severity":"medium","source":"cisa-adp","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-789","name":"Memory Allocation with Excessive Size Value"}],"description":"Issue summary: A TLS 1.3 connection using certificate compression can be\nforced to allocate a large buffer before decompression without checking\nagainst the configured certificate size limit.\n\nImpact summary: An attacker can cause per-connection memory allocations of\nup to approximately 22 MiB and extra CPU work, potentially leading to\nservice degradation or resource exhaustion (Denial of Service).\n\nIn affected configurations, the peer-supplied uncompressed certificate\nlength from a CompressedCertificate message is used to grow a heap buffer\nprior to decompression. This length is not bounded by the max_cert_list\nsetting, which otherwise constrains certificate message sizes. An attacker\ncan exploit this to cause large per-connection allocations followed by\nhandshake failure. No memory corruption or information disclosure occurs.\n\nThis issue only affects builds where TLS 1.3 certificate compression is\ncompiled in (i.e., not OPENSSL_NO_COMP_ALG) and at least one compression\nalgorithm (brotli, zlib, or zstd) is available, and where the compression\nextension is negotiated. Both clients receiving a server CompressedCertificate\nand servers in mutual TLS scenarios receiving a client CompressedCertificate\nare affected. Servers that do not request client certificates are not\nvulnerable to client-initiated attacks.\n\nUsers can mitigate this issue by setting SSL_OP_NO_RX_CERTIFICATE_COMPRESSION\nto disable receiving compressed certificates.\n\nThe FIPS modules in 3.6, 3.5, 3.4 and 3.3 are not affected by this issue,\nas the TLS implementation is outside the OpenSSL FIPS module boundary.\n\nOpenSSL 3.6, 3.5, 3.4 and 3.3 are vulnerable to this issue.\n\nOpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.","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":"TLS 1.3 CompressedCertificate excessive memory allocation","id":"CVE-2025-66199","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"openssl:openssl","products":["openssl:openssl"],"type":null,"year":"2025"},"n_packages":0,"n_references":5,"next":{"headline":"Apache HTTP Server: mod_userdir+suexec bypass via AllowOverride FileInfo","id":"CVE-2025-66200"},"packages":[],"prev":{"headline":"Not used","id":"CVE-2025-66187"},"products":["OpenSSL"],"published":"2026-01-27","related":[{"cvss_score":10,"headline":"Null dereference in n/a","id":"CVE-2009-3245","kev_date_added":null,"published":"2010-03-05"},{"cvss_score":10,"headline":"Memory corruption in n/a","id":"CVE-2006-3738","kev_date_added":null,"published":"2006-09-28"},{"cvss_score":9.8,"headline":"Untrusted Sender DN Used as Format String in CMP Response Validation","id":"CVE-2026-63073","kev_date_added":null,"published":"2026-08-25"},{"cvss_score":9.8,"headline":"Use after free in n/a","id":"CVE-2016-6309","kev_date_added":null,"published":"2016-09-26"},{"cvss_score":9.8,"headline":"Integer overflow in n/a","id":"CVE-2016-0799","kev_date_added":null,"published":"2016-03-03"},{"cvss_score":9.8,"headline":"Memory corruption in n/a","id":"CVE-2016-2842","kev_date_added":null,"published":"2016-03-03"},{"cvss_score":9.8,"headline":"Memory corruption in n/a","id":"CVE-2003-0545","kev_date_added":null,"published":"2003-10-01"}],"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":"2026-01-29","vendors":["OpenSSL"]},"summary":null,"url":"https://insights.sbomify.com/CVE-2025-66199/"}