Security-check bypass via unverified PTR match
Published Aug 20, 2026 · Updated Aug 20, 2026
Security feature bypass in Bunkerity BunkerWeb before 1.6.13 allows remote attackers to evade rDNS-based filtering via spoofed PTR records. The blacklist.lua, greylist.lua, and antibot.lua modules trust suffix matches in IGNORE_RDNS, GREYLIST_RDNS, and ANTIBOT_IGNORE_RDNS and skip calling get_ips to verify that the claimed hostname resolves back to the client IP. Reachability requires control of a PTR record for the attacking address; the result is blacklist bypass, greylist treatment, or challenge suppression rather than direct code execution or data access.
Summary
What happened
Security feature bypass in Bunkerity BunkerWeb before 1.6.13 allows remote attackers to evade rDNS-based filtering via spoofed PTR records. The blacklist.lua, greylist.lua, and antibot.lua modules trust suffix matches in IGNORE_RDNS, GREYLIST_RDNS, and ANTIBOT_IGNORE_RDNS and skip calling get_ips to verify that the claimed hostname resolves back to the client IP. Reachability requires control of a PTR record for the attacking address; the result is blacklist bypass, greylist treatment, or challenge suppression rather than direct code execution or data access.
The record
- CVE
- CVE-2026-75514
- Published
- Aug 20, 2026
- Updated
- Aug 20, 2026
- Vendor
- Bunkerity
- Product
- BunkerWeb
- Classifications
- CWE-350, T1036
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 20, 2026CVE publishedPublication date reported by the CVE source.
- Aug 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 1.6.13
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- PoC in GHSA-q54j-5484-pvjmproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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