{"answers":{"affected":"5 open source packages ship an affected version, including github.com/caddyserver/caddy/v2 and github.com/caddyserver/caddy. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-52845 exists.","fix":"Upgrade github.com/caddyserver/caddy/v2 to 2.11.4 or later.","what":"CVE-2026-52845 is a high-severity authentication bypass vulnerability in caddyserver caddy, published on 23 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-52845 and fix it if it is affected.\n\nWhat it is: CVE-2026-52845 is a high-severity authentication bypass vulnerability in caddyserver caddy, published on 23 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-52845 exists.\n\nAffected packages and fixed versions:\n- github.com/caddyserver/caddy/v2 (Go): affected all versions; fixed in 2.11.4\n- github.com/caddyserver/caddy/v2 (Go): affected all versions; fixed in 2.11.4\n- github.com/caddyserver/caddy/v2 (Go): affected all versions; fixed in 2.11.4\n- github.com/caddyserver/caddy (Go): affected all versions up to 1.0.5; no fix listed\n- github.com/caddyserver/caddy (Go): affected all versions up to 1.0.5; 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-2026-52845/ (Markdown: https://insights.sbomify.com/CVE-2026-52845/index.md)","id":"CVE-2026-52845","markdown":"https://insights.sbomify.com/CVE-2026-52845/index.md","name":"CVE-2026-52845","record":{"aliases":["CLEANSTART-2026-DI50489","DEBIAN-CVE-2026-52845","GHSA-f59h-q822-g45g","GO-2026-5346","MINI-9236-f2jv-m5g5","MINI-9jhw-j2hq-p4vc","UBUNTU-CVE-2026-52845"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["privilege_escalation","security_bypass"],"network_reachable":"yes","non_default_config":true,"product_category":"Caddy web server","requires_auth":"low_privilege","summary":"Remote attackers can bypass forward authentication checks by exploiting header normalization differences, allowing them to inject trusted identity headers into PHP/FastCGI applications.","user_interaction":"not_required","vuln_class":"auth_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"caddy","vendor":"caddyserver"}],"cvss":{"score":8.1,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-444","name":"Inconsistent Interpretation of HTTP Requests"},{"id":"CWE-290","name":"Authentication Bypass by Spoofing"},{"id":"CWE-287","name":"Improper Authentication"}],"description":"Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, forward_auth copy_headers deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through php_fastcgi, Caddy normalizes HTTP headers into CGI variables by replacing - with _. This lets a client send an underscore alias that survives the forward_auth delete step but becomes the same PHP/FastCGI variable. Result: a remote client can inject or sometimes override identity/group headers trusted by PHP/FastCGI applications behind Caddy. This vulnerability is fixed in 2.11.4.","ecosystems":["Go"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"Caddy: FastCGI header normalization bypass in `forward_auth copy_headers`","id":"CVE-2026-52845","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Go","product":null,"products":[],"type":"auth_bypass","year":"2026"},"n_packages":5,"n_references":1,"next":{"headline":"Caddy: stripHTML template function bypass","id":"CVE-2026-52846"},"packages":[{"ecosystem":"Go","fixed":[],"introduced":["0"],"last_affected":["1.0.5"],"package":"github.com/caddyserver/caddy","purl":null,"source":"GHSA-f59h-q822-g45g"},{"ecosystem":"Go","fixed":[],"introduced":["0"],"last_affected":["1.0.5"],"package":"github.com/caddyserver/caddy","purl":"pkg:golang/github.com/caddyserver/caddy","source":"GHSA-f59h-q822-g45g"},{"ecosystem":"Go","fixed":["2.11.4"],"introduced":["0"],"last_affected":[],"package":"github.com/caddyserver/caddy/v2","purl":null,"source":"GHSA-f59h-q822-g45g"},{"ecosystem":"Go","fixed":["2.11.4"],"introduced":["0"],"last_affected":[],"package":"github.com/caddyserver/caddy/v2","purl":"pkg:golang/github.com/caddyserver/caddy/v2","source":"GHSA-f59h-q822-g45g"},{"ecosystem":"Go","fixed":["2.11.4"],"introduced":["0"],"last_affected":[],"package":"github.com/caddyserver/caddy/v2","purl":"pkg:golang/github.com/caddyserver/caddy/v2","source":"GO-2026-5346"}],"prev":{"headline":"Caddy: Windows `file_server` path authorization bypass via encoded backslash","id":"CVE-2026-52844"},"products":["caddy"],"published":"2026-06-23","related":[{"cvss_score":9.8,"headline":"Caddy vulnerable to Authentication Bypass due to mishandling of TLS client authentication","id":"CVE-2018-21246","kev_date_added":null,"published":"2020-06-15"},{"cvss_score":8.9,"headline":"Caddy: Unicode case-folding length expansion causes incorrect split_path index in FastCGI transport","id":"CVE-2026-27590","kev_date_added":null,"published":"2026-02-24"},{"cvss_score":8.8,"headline":"Caddy's mTLS client authentication silently fails open when CA certificate file is missing or malformed","id":"CVE-2026-27586","kev_date_added":null,"published":"2026-02-24"},{"cvss_score":8.1,"headline":"Caddy: Unsafe Unicode Handling in FastCGI splitPos Allows Execution of Non-PHP Files","id":"CVE-2026-45135","kev_date_added":null,"published":"2026-06-23"},{"cvss_score":8.1,"headline":"Caddy forward_auth copy_headers Does Not Strip Client-Supplied Headers, Allowing Identity Injection and Privilege Escalation","id":"CVE-2026-30851","kev_date_added":null,"published":"2026-03-07"},{"cvss_score":7.7,"headline":"Caddy: MatchPath %xx (escaped-path) branch skips case normalization, enabling path-based route/auth bypass","id":"CVE-2026-27587","kev_date_added":null,"published":"2026-02-24"}],"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":"CC BY 4.0","name":"Go Vulnerability Database","prefix":"GO"},{"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":"poc","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-07-15","vendors":["caddyserver"]},"summary":"Remote attackers can bypass forward authentication checks by exploiting header normalization differences, allowing them to inject trusted identity headers into PHP/FastCGI applications.","url":"https://insights.sbomify.com/CVE-2026-52845/"}