Caddy is an extensible server platform that uses TLS by default
Why It Matters
Analysis dossierWhy It Matters
Caddy is an extensible server platform that uses TLS by default. From 2.7.0 until 2.11.3, the FastCGI transport's splitPos() in modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go misuses golang.org/x/text/search with search.IgnoreCase when the request path contains a non-ASCII byte. Two distinct flaws in that fallback let an attacker mislead Caddy's FastCGI splitting into treating a non-.php (or other configured split_path extension) file as a script. In any deployment where the attacker can place content into a file served via FastCGI (uploads, file storage, etc.), this can be escalated to remote code execution by crafting a URL whose path triggers either flaw. This vulnerability is fixed in 2.11.3.
High
Unknown
Unknown
Risk basis: SOC ecosystem technology relevance; HIGH severity; Source severity; no confirmed exploitation signal
Affected Products & Remediation
1 source-backed product- caddyserver caddy · >= 2.7.0 < 2.11.3 · NVD CPE · Source
Vendor or catalog guidance (source)
Not provided by source
Known exploitation (source facts)
Only what a source states. Unknown means no source has said either way; it is not "not exploited".
- CISA KEV
- Unknown
- Exploited (source statement)
- Unknown
- Publicly disclosed (source)
- Unknown
Suggested hunting (rule-based inference)
SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.
Matched network-unauthenticated (CVSS AV:N, CVSS PR:N, CVSS UI:N)
Exposure
- Identify devices reporting this CVE and note which expose the affected service to untrusted networks.Telemetry: DeviceTvmSoftwareVulnerabilities · A network-reachable, no-privilege vector makes internet-facing instances the first exposure question. · Rule network-unauthenticated
Exploitation evidence
- Review inbound connections to the affected service from unexpected sources since the advisory date.Telemetry: DeviceNetworkEvents · Hunting hypothesis from the CVSS vector; it does not show that exploitation occurred. · Rule network-unauthenticated
Response
- Confirm the source-stated update is installed and the CVE is no longer reported.Telemetry: DeviceTvmSoftwareVulnerabilities · A follow-up inventory check verifies remediation. · Rule network-unauthenticated
CISA KEV Record
CISA KEV status was not determined for this record.
Change History & Source Data
— No recorded material change
- CNA / source
- security-advisories@github.com
- Record status · verification
- UPDATED · NVD API
- CPE
- cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:*
Evidence & Provenance
Linked by the query's stored exact CVE association. Review required tables and validation status before use.
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2026-45135"| project DeviceId, DeviceName, OSPlatform, OSVersion, SoftwareVendor, SoftwareName, SoftwareVersion, CveId, VulnerabilitySeverityLevel, RecommendedSecurityUpdate, RecommendedSecurityUpdateId| sort by VulnerabilitySeverityLevel descLooking up related community queries…