{"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-2026-34480 in the wild and no public exploit code.","fix":"Upgrade org.apache.logging.log4j:log4j-core to 2.25.4 or later.","what":"CVE-2026-34480 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-2026-34480 and fix it if it is affected.\n\nWhat it is: CVE-2026-34480 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-2026-34480 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- org.apache.logging.log4j:log4j-core (Maven): affected from 2.0-alpha1; fixed in 2.25.4\n- org.apache.logging.log4j:log4j-core (Maven): affected from 2.0-alpha1; fixed in 2.25.4\n- org.apache.logging.log4j:log4j-core (Maven): affected from 3.0.0-alpha1 up to 3.0.0-beta3; no fix listed\n- org.apache.logging.log4j:log4j-core (Maven): affected from 3.0.0-alpha1 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-2026-34480/ (Markdown: https://insights.sbomify.com/CVE-2026-34480/index.md)","id":"CVE-2026-34480","markdown":"https://insights.sbomify.com/CVE-2026-34480/index.md","name":"CVE-2026-34480","record":{"aliases":["CLEANSTART-2026-BH90179","CLEANSTART-2026-GM49347","CLEANSTART-2026-JA22493","CLEANSTART-2026-JH04977","CLEANSTART-2026-OV82681","CLEANSTART-2026-YQ06926","CLSA-2026-1790872128","CLSA-2026-1791190936","CLSA-2026-1792102359","CLSA-2026-1792577744","CLSA-2026-1792694422","CLSA-2026-1792694968","CLSA-2026-1793191907","DEBIAN-CVE-2026-34480","ECHO-2fdc-9fb7-c602","GHSA-3pxv-7cmr-fjr4","MINI-2589-36pf-gwmm","MINI-268h-qw5h-mhqh","MINI-28gp-6rr2-24m7","MINI-2hqc-qjfr-jrgp","MINI-2mhq-p778-4wwp","MINI-2v83-3pfr-wcpf","MINI-32m4-cjmq-q78f","MINI-32p2-96qj-fxqx","MINI-3923-684f-cqp2","MINI-3hhg-jppj-8mp2","MINI-43mr-cfvq-464g","MINI-45wq-pj9w-4vwr","MINI-4hrw-4g69-8vg5","MINI-4mv8-g575-pg3p","MINI-4mx3-p93p-fc4f","MINI-4rh7-cc9x-jmmf","MINI-568v-9j7v-9h5q","MINI-5c62-vfhc-7v5j","MINI-5q6x-7jgg-98j3","MINI-6jc4-j29r-v84p","MINI-6p37-5j3c-w2vr","MINI-6r4r-fgjg-j4q2","MINI-7ghf-qjxg-p3vc","MINI-7hvg-j6jr-4fgj","MINI-7j2p-vcg4-8f24","MINI-7x2q-xxj2-q9h6","MINI-87xc-xjx6-9864","MINI-8fhg-pv9x-jh34","MINI-8ppp-gvqm-22wq","MINI-8q2w-7frq-hqjv","MINI-95xm-p5qh-x6fq","MINI-9hmj-qm66-jwqf","MINI-9pwq-cr7m-672g","MINI-9rq7-4gqc-qhp8","MINI-9rr6-prjm-f28w","MINI-c2xm-w5v6-rgcj","MINI-c3vg-wf42-95jf","MINI-c8x7-xg2x-fg47","MINI-c8x8-8cmw-p5c5","MINI-cqv8-m92q-9f3m","MINI-cw4r-7xq7-99v9","MINI-f3p5-xj94-3mrv","MINI-ffc9-cr6w-jr28","MINI-g9pp-75j4-qpjm","MINI-h283-mv2f-hrrh","MINI-h38g-4h2f-qqcj","MINI-h94q-r36w-x3qp","MINI-hp9h-5p3h-8m3x","MINI-hqqc-xxr4-mwhj","MINI-j37p-c735-25hq","MINI-j66x-9cqx-hmj5","MINI-m3hm-68vp-7rqj","MINI-m88j-mrfv-fj6j","MINI-mfhj-v9fx-vf33","MINI-mpc4-5r8v-v3fx","MINI-p6r2-cg5f-h785","MINI-p934-hhvm-f2hq","MINI-pc6f-986x-g2q5","MINI-pjf5-8gxj-fvcq","MINI-pqc5-hpq2-x6wg","MINI-px28-77w9-pgw4","MINI-q44j-gchf-6qj2","MINI-q7c2-4wj7-g473","MINI-qm8c-rjf2-wwc3","MINI-qwpw-vcqc-p2j2","MINI-rc7m-jv9h-cf7p","MINI-rf2r-32gg-78h8","MINI-rq57-m8w3-x28p","MINI-rxqp-gq37-vwff","MINI-v4c6-mx66-v3q9","MINI-v5pv-jmfg-52fm","MINI-v8j2-h48g-gmvv","MINI-v8wf-fg93-qq8c","MINI-vgh2-px44-g6wf","MINI-vh47-rcr2-4v67","MINI-vh94-hrgj-fwcf","MINI-vqc5-xpcm-rg6m","MINI-vqj9-7mjr-qqxm","MINI-vvcp-f7q9-97mw","MINI-w37c-74gh-5m5j","MINI-w7qj-h8h7-78mm","MINI-wc2p-mpmq-jxjh","MINI-wcp7-895c-35rj","MINI-wg72-h3f4-hwcg","MINI-wr69-56gx-27pw","MINI-x3xx-frrw-hhr4","MINI-x6v4-cwgm-gp2q","MINI-xcvh-hxgh-rvm8","MINI-xqg2-gpph-j75r","MINI-xr52-vx63-g5c9","ROOT-APP-MAVEN-CVE-2026-34480","UBUNTU-CVE-2026-34480"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Java logging library","requires_auth":"none","summary":"Attackers can cause log event loss or malformed XML output in Apache Log4j by injecting forbidden characters, potentially disrupting log processing.","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-116","name":"Improper Encoding or Escaping of Output"}],"description":"Apache Log4j Core's  XmlLayout https://logging.apache.org/log4j/2.x/manual/layouts.html#XmlLayout , in versions up to and including 2.25.3, fails to sanitize characters forbidden by the  XML 1.0 specification https://www.w3.org/TR/xml/#charsets  producing invalid XML output whenever a log message or MDC value contains such characters.\n\nThe impact depends on the StAX implementation in use:\n\n  *  JRE built-in StAX: Forbidden characters are silently written to the output, producing malformed XML. Conforming parsers must reject such documents with a fatal error, which may cause downstream log-processing systems to drop the affected records.\n  *  Alternative StAX implementations (e.g.,  Woodstox https://github.com/FasterXML/woodstox , a transitive dependency of the Jackson XML Dataformat module): An exception is thrown during the logging call, and the log event is never delivered to its intended appender, only to Log4j's internal status logger.\n\nUsers are advised to upgrade to Apache Log4j Core 2.25.4, which corrects this issue by sanitizing forbidden characters before XML output.","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: Silent log event loss in XmlLayout due to unescaped XML 1.0 forbidden characters","id":"CVE-2026-34480","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 JSON Template Layout: Improper serialization of non-finite floating-point values in JsonTemplateLayout","id":"CVE-2026-34481"},"packages":[{"ecosystem":"Maven","fixed":["2.25.4"],"introduced":["2.0-alpha1"],"last_affected":[],"package":"org.apache.logging.log4j:log4j-core","purl":null,"source":"GHSA-3pxv-7cmr-fjr4"},{"ecosystem":"Maven","fixed":["2.25.4"],"introduced":["2.0-alpha1"],"last_affected":[],"package":"org.apache.logging.log4j:log4j-core","purl":"pkg:maven/org.apache.logging.log4j/log4j-core","source":"GHSA-3pxv-7cmr-fjr4"},{"ecosystem":"Maven","fixed":[],"introduced":["3.0.0-alpha1"],"last_affected":["3.0.0-beta3"],"package":"org.apache.logging.log4j:log4j-core","purl":null,"source":"GHSA-3pxv-7cmr-fjr4"},{"ecosystem":"Maven","fixed":[],"introduced":["3.0.0-alpha1"],"last_affected":["3.0.0-beta3"],"package":"org.apache.logging.log4j:log4j-core","purl":"pkg:maven/org.apache.logging.log4j/log4j-core","source":"GHSA-3pxv-7cmr-fjr4"}],"prev":{"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"},"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 cause log event loss or malformed XML output in Apache Log4j by injecting forbidden characters, potentially disrupting log processing.","url":"https://insights.sbomify.com/CVE-2026-34480/"}