{"id":"CVE-2026-75514","aliases":["EUVD-2026-63542","GHSA-q54j-5484-pvjm"],"status":"published","title":"BunkerWeb: rDNS bypass via missing forward-confirmation (FCrDNS) in blacklist, greylist, and antibot","description":"BunkerWeb is an open-source, next-generation Web Application Firewall. Prior to 1.6.13, the blacklist, greylist, and antibot modules in src/common/core/blacklist/blacklist.lua, src/common/core/greylist/greylist.lua, and src/common/core/antibot/antibot.lua trust PTR suffix matches in IGNORE_RDNS, GREYLIST_RDNS, and ANTIBOT_IGNORE_RDNS without using get_ips to confirm that the hostname resolves to the client address. An unauthenticated remote attacker who controls a PTR record can spoof a trusted suffix to bypass rDNS-based blacklisting, gain greylist treatment, or skip an antibot challenge. This issue is fixed in version 1.6.13.","severity":{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00597,"percentile":0.49029,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-350"],"published":"2026-08-20T18:31:51Z","modified":"2026-10-28T02:30:54Z","products":[{"vendor":"bunkerity","product":"bunkerweb"}],"references":[{"url":"https://github.com/bunkerity/bunkerweb/security/advisories/GHSA-q54j-5484-pvjm","tags":["x_refsource_CONFIRM","exploit","advisory"]},{"url":"https://github.com/bunkerity/bunkerweb/pull/3710","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/bunkerity/bunkerweb/commit/1a97e5b3f977130a1b84507a9e1f703c8eec12eb","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/bunkerity/bunkerweb/releases/tag/v1.6.13","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/75xxx/CVE-2026-75514.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-75514","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-75514","title":"BunkerWeb: rDNS bypass via missing forward-confirmation (FCrDNS) in blacklist, greylist, and antibot","description":"BunkerWeb is an open-source, next-generation Web Application Firewall. Prior to 1.6.13, the blacklist, greylist, and antibot modules in src/common/core/blacklist/blacklist.lua, src/common/core/greylist/greylist.lua, and src/common/core/antibot/antibot.lua trust PTR suffix matches in IGNORE_RDNS, GREYLIST_RDNS, and ANTIBOT_IGNORE_RDNS without using get_ips to confirm that the hostname resolves to the client address. An unauthenticated remote attacker who controls a PTR record can spoof a trusted suffix to bypass rDNS-based blacklisting, gain greylist treatment, or skip an antibot challenge. This issue is fixed in version 1.6.13.","status":"published","published":"2026-08-20T18:31:51.527Z","modified":"2026-08-20T19:00:33.894Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-350"],"updated_at":"2026-11-02T14:20:07.260654Z"}],"euvd":[{"id":"EUVD-2026-63542","description":"BunkerWeb is an open-source, next-generation Web Application Firewall. Prior to 1.6.13, the blacklist, greylist, and antibot modules in src/common/core/blacklist/blacklist.lua, src/common/core/greylist/greylist.lua, and src/common/core/antibot/antibot.lua trust PTR suffix matches in IGNORE_RDNS, GREYLIST_RDNS, and ANTIBOT_IGNORE_RDNS without using get_ips to confirm that the hostname resolves to the client address. An unauthenticated remote attacker who controls a PTR record can spoof a trusted suffix to bypass rDNS-based blacklisting, gain greylist treatment, or skip an antibot challenge. This issue is fixed in version 1.6.13.","status":"published","published":"2026-08-20T18:31:51Z","modified":"2026-08-20T19:00:33Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"medium"}],"updated_at":"2026-11-02T18:01:38.846525Z"}],"nvd":[{"id":"CVE-2026-75514","description":"BunkerWeb is an open-source, next-generation Web Application Firewall. Prior to 1.6.13, the blacklist, greylist, and antibot modules in src/common/core/blacklist/blacklist.lua, src/common/core/greylist/greylist.lua, and src/common/core/antibot/antibot.lua trust PTR suffix matches in IGNORE_RDNS, GREYLIST_RDNS, and ANTIBOT_IGNORE_RDNS without using get_ips to confirm that the hostname resolves to the client address. An unauthenticated remote attacker who controls a PTR record can spoof a trusted suffix to bypass rDNS-based blacklisting, gain greylist treatment, or skip an antibot challenge. This issue is fixed in version 1.6.13.","status":"published","published":"2026-08-20T19:17:03.637Z","modified":"2026-10-18T20:10:00.11Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-350"],"updated_at":"2026-11-02T14:12:40.302911Z"}],"osv":[{"id":"CVE-2026-75514","title":"BunkerWeb: rDNS bypass via missing forward-confirmation (FCrDNS) in blacklist, greylist, and antibot","description":"BunkerWeb is an open-source, next-generation Web Application Firewall. Prior to 1.6.13, the blacklist, greylist, and antibot modules in src/common/core/blacklist/blacklist.lua, src/common/core/greylist/greylist.lua, and src/common/core/antibot/antibot.lua trust PTR suffix matches in IGNORE_RDNS, GREYLIST_RDNS, and ANTIBOT_IGNORE_RDNS without using get_ips to confirm that the hostname resolves to the client address. An unauthenticated remote attacker who controls a PTR record can spoof a trusted suffix to bypass rDNS-based blacklisting, gain greylist treatment, or skip an antibot challenge. This issue is fixed in version 1.6.13.","status":"published","published":"2026-08-20T18:31:51.527Z","modified":"2026-10-28T02:30:54.631763329Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"medium"}],"cwes":["CWE-350"],"updated_at":"2026-11-02T15:45:17.102988Z"}]}}