{"answers":{"affected":"4 open source packages ship an affected version, including org.apache.logging.log4j:log4j-core. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-34478 in the wild and no public exploit code.","fix":"Upgrade org.apache.logging.log4j:log4j-core to 2.25.4 or later.","what":"CVE-2026-34478 is a medium-severity vulnerability in Apache Log4j Core, published on 10 Apr 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-2026-34478 and fix it if it is affected.\n\nWhat it is: CVE-2026-34478 is a medium-severity vulnerability in Apache Log4j Core, published on 10 Apr 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-2026-34478 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- org.apache.logging.log4j:log4j-core (Maven): affected from 2.21.0; fixed in 2.25.4\n- org.apache.logging.log4j:log4j-core (Maven): affected from 2.21.0; fixed in 2.25.4\n- org.apache.logging.log4j:log4j-core (Maven): affected from 3.0.0-beta1 up to 3.0.0-beta3; no fix listed\n- org.apache.logging.log4j:log4j-core (Maven): affected from 3.0.0-beta1 up to 3.0.0-beta3; no fix listed\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-2026-34478/ (Markdown: https://insights.sbomify.com/CVE-2026-34478/index.md)","id":"CVE-2026-34478","markdown":"https://insights.sbomify.com/CVE-2026-34478/index.md","name":"CVE-2026-34478","record":{"aliases":["CLEANSTART-2026-CP64029","CLEANSTART-2026-DZ37385","CLEANSTART-2026-GW86512","CLEANSTART-2026-ZG68891","CLEANSTART-2026-ZR66277","ECHO-d811-dae2-2041","GHSA-445c-vh5m-36rj","MINI-26xc-8vr3-f3fg","MINI-2r54-3prx-9jh3","MINI-2vv6-9h26-723j","MINI-3gp9-x68q-ghv2","MINI-4f39-xgm4-mh8x","MINI-4v9c-p23j-wfq8","MINI-5cgq-gvph-69h2","MINI-5f3g-pxv5-9fp7","MINI-5f68-qp9h-jm4p","MINI-65j6-798c-5wvm","MINI-65w8-vm9x-whh7","MINI-682j-hww5-hg74","MINI-6g38-pm39-wrxr","MINI-7p8v-pcx8-ppc9","MINI-7pp3-86vf-grj2","MINI-856j-g8f6-wcq6","MINI-8gwp-78hv-c82c","MINI-8r9m-7g9m-gjpp","MINI-8rgw-fqhq-x5cc","MINI-93xh-cq2w-3c85","MINI-9g2g-j229-mf24","MINI-9mw4-rxjv-88hx","MINI-ccmj-w57x-22r8","MINI-f44g-wfgp-php8","MINI-f49v-36vg-4g4f","MINI-f6xg-5rmv-6x82","MINI-f9hp-q6qj-hrfr","MINI-fmf3-j6ch-r275","MINI-g5gr-qfcj-j5p9","MINI-g6j4-qp2v-938x","MINI-g7fc-xgfq-2hv2","MINI-h4gc-m9jp-2g7j","MINI-h85v-x485-4jv4","MINI-h8j5-hv3q-6vcr","MINI-hgf6-jcwj-x76v","MINI-hqf3-j5pq-fmvq","MINI-j2p4-6hrx-qw3p","MINI-j595-j9g2-4r74","MINI-jjq2-pgqw-h743","MINI-jwfq-prgm-w3v6","MINI-m9mv-3298-99fr","MINI-mf3q-m5f3-p7wv","MINI-mf4v-fg2p-vqj6","MINI-mj9v-xc64-pc5j","MINI-p257-9h6w-64mq","MINI-p68x-2c4r-gfq6","MINI-p75m-m7m8-j4rr","MINI-p9vg-28q5-3x55","MINI-pcr2-qxm4-9q8w","MINI-pmfv-fv53-qjwg","MINI-q3r8-fhw2-4xgh","MINI-q839-cpcx-3pm2","MINI-rr49-9pp7-q4p8","MINI-vcwv-r5j3-rq77","MINI-vp58-g7p9-hr4x","MINI-w27m-xwwj-mj8p","MINI-wqrq-hwv6-q872","MINI-wr3w-3xcq-v7m4","MINI-x672-vw6c-p392","MINI-xfw5-pvqf-x3q7","MINI-xg67-372m-9rmf","MINI-xh2m-5c7f-gfcq","MINI-xmc7-753c-qvwh","MINI-xpr8-mc5g-rqx8","MINI-xwgh-6375-pvwh","MINI-xxcj-w7qr-ccqg","ROOT-APP-MAVEN-CVE-2026-34478","UBUNTU-CVE-2026-34478"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_modify","security_bypass"],"network_reachable":"yes","non_default_config":true,"product_category":"Java logging library","requires_auth":"none","summary":"Attackers can inject CRLF sequences into logs via Rfc5424Layout due to silent configuration renames, affecting users with specific syslog setups.","user_interaction":"not_required","vuln_class":"other"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"apache","cpe":[{"product":"log4j","vendor":"apache"}],"cvss":{"score":6.9,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N","version":"4.0"},"cwes":[{"id":"CWE-684","name":"Incorrect Provision of Specified Functionality"},{"id":"CWE-117","name":"Improper Output Neutralization for Logs"}],"description":"Apache Log4j Core's  Rfc5424Layout https://logging.apache.org/log4j/2.x/manual/layouts.html#RFC5424Layout , in versions 2.21.0 through 2.25.3, is vulnerable to log injection via CRLF sequences due to undocumented renames of security-relevant configuration attributes.\n\nTwo distinct issues affect users of stream-based syslog services who configure Rfc5424Layout directly:\n\n  *  The newLineEscape attribute was silently renamed, causing newline escaping to stop working for users of TCP framing (RFC 6587), exposing them to CRLF injection in log output.\n  *  The useTlsMessageFormat attribute was silently renamed, causing users of TLS framing (RFC 5425) to be silently downgraded to unframed TCP (RFC 6587), without newline escaping.\n\nUsers of the SyslogAppender are not affected, as its configuration attributes were not modified.\n\nUsers are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue.","ecosystems":["Maven"],"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":"Apache Log4j Core: Log injection in Rfc5424Layout due to silent configuration incompatibility","id":"CVE-2026-34478","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Maven","product":null,"products":[],"type":"other","year":"2026"},"n_packages":4,"n_references":5,"next":{"headline":"Apache Log4j 1 to Log4j 2 bridge: silent log event loss in Log4j1XmlLayout due to unescaped XML 1.0 forbidden characters","id":"CVE-2026-34479"},"packages":[{"ecosystem":"Maven","fixed":["2.25.4"],"introduced":["2.21.0"],"last_affected":[],"package":"org.apache.logging.log4j:log4j-core","purl":null,"source":"GHSA-445c-vh5m-36rj"},{"ecosystem":"Maven","fixed":["2.25.4"],"introduced":["2.21.0"],"last_affected":[],"package":"org.apache.logging.log4j:log4j-core","purl":"pkg:maven/org.apache.logging.log4j/log4j-core","source":"GHSA-445c-vh5m-36rj"},{"ecosystem":"Maven","fixed":[],"introduced":["3.0.0-beta1"],"last_affected":["3.0.0-beta3"],"package":"org.apache.logging.log4j:log4j-core","purl":null,"source":"GHSA-445c-vh5m-36rj"},{"ecosystem":"Maven","fixed":[],"introduced":["3.0.0-beta1"],"last_affected":["3.0.0-beta3"],"package":"org.apache.logging.log4j:log4j-core","purl":"pkg:maven/org.apache.logging.log4j/log4j-core","source":"GHSA-445c-vh5m-36rj"}],"prev":{"headline":"Apache Log4j Core: `verifyHostName` attribute silently ignored in TLS configuration","id":"CVE-2026-34477"},"products":["Apache Log4j Core"],"published":"2026-04-10","related":[{"cvss_score":10,"headline":"Apache Log4j2 Remote Code Execution","id":"CVE-2021-44228","kev_date_added":"2021-12-10","published":"2021-12-10"},{"cvss_score":9,"headline":"Apache Log4j2 Deserialization of Untrusted Data","id":"CVE-2021-45046","kev_date_added":"2023-05-01","published":"2021-12-14"},{"cvss_score":9.8,"headline":"SQL injection in JDBC Appender in Apache Log4j V1","id":"CVE-2022-23305","kev_date_added":null,"published":"2022-01-18"},{"cvss_score":9.8,"headline":"Deserialization of Untrusted Data in Log4j","id":"CVE-2017-5645","kev_date_added":null,"published":"2017-04-17"},{"cvss_score":8.8,"headline":"Deserialization of untrusted data in JMSSink in Apache Log4j 1.x","id":"CVE-2022-23302","kev_date_added":null,"published":"2022-01-18"},{"cvss_score":7.5,"headline":"Apache Log4j 1.x (EOL) allows DoS in Chainsaw and SocketAppender","id":"CVE-2023-26464","kev_date_added":null,"published":"2023-03-10"},{"cvss_score":7.5,"headline":"Deserialization of untrusted data in JMSAppender in Apache Log4j 1.2","id":"CVE-2021-4104","kev_date_added":null,"published":"2021-12-14"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"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":"2026-04-10","vendors":["Apache Software Foundation"]},"summary":"Attackers can inject CRLF sequences into logs via Rfc5424Layout due to silent configuration renames, affecting users with specific syslog setups.","url":"https://insights.sbomify.com/CVE-2026-34478/"}