{"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-2026-34477 in the wild and no public exploit code.","fix":"Upgrade org.apache.logging.log4j:log4j-core to 2.25.4 or later.","what":"CVE-2026-34477 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-2026-34477 and fix it if it is affected.\n\nWhat it is: CVE-2026-34477 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-2026-34477 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- org.apache.logging.log4j:log4j-core (Maven): affected from 2.12.0; fixed in 2.25.4\n- org.apache.logging.log4j:log4j-core (Maven): affected from 2.12.0; 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-2026-34477/ (Markdown: https://insights.sbomify.com/CVE-2026-34477/index.md)","id":"CVE-2026-34477","markdown":"https://insights.sbomify.com/CVE-2026-34477/index.md","name":"CVE-2026-34477","record":{"aliases":["CLEANSTART-2026-IQ12503","CLEANSTART-2026-KO79876","CLEANSTART-2026-QJ40083","CLEANSTART-2026-VD23579","CLEANSTART-2026-YX55507","CLSA-2026-1779929356","CLSA-2026-1791819410","CLSA-2026-1791901346","ECHO-a45f-aad1-7c04","GHSA-6hg6-v5c8-fphq","MINI-22wx-cwc8-qc7h","MINI-27f7-p329-r266","MINI-2988-wxcf-mhfx","MINI-29rw-3f2p-2p5w","MINI-2cmx-8rvj-5x8w","MINI-2mg3-cvrg-554p","MINI-2p3h-hjxx-3hw7","MINI-37w4-458c-4hw5","MINI-3cg3-3gxh-wqmw","MINI-3gm6-mc5g-92qm","MINI-3pw2-r9qj-8c6v","MINI-3r2h-5cc5-3v95","MINI-3r5x-57m5-727m","MINI-4fcc-gqxx-9334","MINI-4m5f-v537-jcc7","MINI-4w35-2h9f-jfgh","MINI-576r-cvcv-xjrg","MINI-5jhg-7wqx-4mgr","MINI-62c7-p8v2-6rpq","MINI-638m-7wvr-8f4c","MINI-63wj-vqwm-2q75","MINI-6fm2-g323-987m","MINI-6jq4-g6xr-j28f","MINI-6p4g-4q8c-8pgf","MINI-6pq6-xv8j-fppf","MINI-72fv-r7cj-5mvh","MINI-72mg-8mr7-gw75","MINI-7672-v4mm-ppgx","MINI-7g5w-wjm5-wm5m","MINI-7v57-7gxh-3mhr","MINI-7wwq-v4gv-qrp6","MINI-899g-jq5x-48hq","MINI-8rgv-899p-72g4","MINI-8rx5-2g2r-2pc6","MINI-9446-8fgf-prv7","MINI-94hm-8w4m-2p2j","MINI-9688-523q-rfpr","MINI-973j-54m6-c824","MINI-99vh-g85p-g7vg","MINI-9jg3-83jp-32c9","MINI-9x53-frwm-36h9","MINI-c2ph-67v4-jqxh","MINI-c2v9-3f22-953m","MINI-c6xq-9vwm-p94c","MINI-c7qp-v98p-6cw9","MINI-cfcf-v8xv-9rrw","MINI-cg8m-m9hc-v2mp","MINI-cm99-5c2x-x4jj","MINI-cp4x-2g67-73gm","MINI-cp5q-hh26-h9qq","MINI-cx2w-gp7j-jg2w","MINI-f453-5rfg-x936","MINI-fww8-v72f-hx3v","MINI-gr2g-ccxp-cw68","MINI-gr73-gwc9-698q","MINI-jmh3-xcc4-66pc","MINI-jp96-whj7-fpcm","MINI-jv36-x666-qj79","MINI-jv6q-jpjm-6cpf","MINI-m39j-xxm5-g5m8","MINI-m87w-9xxc-2vm2","MINI-mhch-vfcm-jwvj","MINI-mq24-3x2p-xmmg","MINI-mq34-76vm-v93j","MINI-mqj5-q69q-mm85","MINI-mrfm-x857-hhqf","MINI-pf4j-833v-fr45","MINI-pf9x-2c42-4582","MINI-pp77-vw6x-fq92","MINI-pppw-6jrw-8wxr","MINI-q3q6-crwh-v2c4","MINI-q5cv-q3x4-3g2m","MINI-r483-qwc3-7c75","MINI-r4px-m992-f9v2","MINI-r8fm-7gqv-mj67","MINI-r8wr-hq3w-pmgr","MINI-v58g-p2j9-w3g7","MINI-v5cw-2p9h-9gqj","MINI-v698-6pmw-7xxm","MINI-v6q8-6wwv-hvv2","MINI-v8vp-37wx-fv23","MINI-vf8j-74h6-mr68","MINI-vfhv-5hr8-fxwp","MINI-vpxq-wchq-8h23","MINI-wj3v-5f62-x5mr","MINI-wjcg-4r53-qgg2","MINI-wmhq-m9g5-wcw2","MINI-wxwq-h648-pvr5","MINI-x64g-w7qc-3hf5","MINI-xhxw-366g-h8v5","ROOT-APP-MAVEN-CVE-2026-34477","UBUNTU-CVE-2026-34477"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_read","security_bypass"],"network_reachable":"yes","non_default_config":true,"product_category":"Java logging library","requires_auth":"none","summary":"Attackers can perform man-in-the-middle attacks on Log4j TLS connections if the verifyHostName attribute is configured but ignored, bypassing hostname verification.","user_interaction":"not_required","vuln_class":"security_feature_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"apache","cpe":[{"product":"log4j","vendor":"apache"}],"cvss":{"score":6.3,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:L/SA:N","version":"4.0"},"cwes":[{"id":"CWE-295","name":"Improper Certificate Validation"},{"id":"CWE-297","name":"Improper Validation of Certificate with Host Mismatch"}],"description":"The fix for  CVE-2025-68161 https://logging.apache.org/security.html#CVE-2025-68161  was incomplete: it addressed hostname verification only when enabled via the  log4j2.sslVerifyHostName https://logging.apache.org/log4j/2.x/manual/systemproperties.html#log4j2.sslVerifyHostName  system property, but not when configured through the  verifyHostName https://logging.apache.org/log4j/2.x/manual/appenders/network.html#SslConfiguration-attr-verifyHostName  attribute of the \u003cSsl\u003e element.\n\nAlthough the verifyHostName configuration attribute was introduced in Log4j Core 2.12.0, it was silently ignored in all versions through 2.25.3, leaving TLS connections vulnerable to interception regardless of the configured value.\n\nA network-based attacker may be able to perform a man-in-the-middle attack when all of the following conditions are met:\n\n  *  An SMTP, Socket, or Syslog appender is in use.\n  *  TLS is configured via a nested \u003cSsl\u003e element.\n  *  The attacker can present a certificate issued by a CA trusted by the appender's configured trust store, or by the default Java trust store if none is configured.\nThis issue does not affect users of the HTTP appender, which uses a separate  verifyHostname https://logging.apache.org/log4j/2.x/manual/appenders/network.html#HttpAppender-attr-verifyHostName  attribute that was not subject to this bug and verifies host names by default.\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: `verifyHostName` attribute silently ignored in TLS configuration","id":"CVE-2026-34477","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Maven","product":null,"products":[],"type":"security_feature_bypass","year":"2026"},"n_packages":4,"n_references":5,"next":{"headline":"Apache Log4j Core: Log injection in Rfc5424Layout due to silent configuration incompatibility","id":"CVE-2026-34478"},"packages":[{"ecosystem":"Maven","fixed":["2.25.4"],"introduced":["2.12.0"],"last_affected":[],"package":"org.apache.logging.log4j:log4j-core","purl":null,"source":"GHSA-6hg6-v5c8-fphq"},{"ecosystem":"Maven","fixed":["2.25.4"],"introduced":["2.12.0"],"last_affected":[],"package":"org.apache.logging.log4j:log4j-core","purl":"pkg:maven/org.apache.logging.log4j/log4j-core","source":"GHSA-6hg6-v5c8-fphq"},{"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-6hg6-v5c8-fphq"},{"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-6hg6-v5c8-fphq"}],"prev":{"headline":"Apache SkyWalking MCP: Server-Side Request Forgery via SW-URL Header in MCP Server","id":"CVE-2026-34476"},"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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-04-10","vendors":["Apache Software Foundation"]},"summary":"Attackers can perform man-in-the-middle attacks on Log4j TLS connections if the verifyHostName attribute is configured but ignored, bypassing hostname verification.","url":"https://insights.sbomify.com/CVE-2026-34477/"}