CVE-2026-45692: caddyserver caddy Partial String Comparison
Vulnerability summary
CVE-2026-45692 is a medium (CVSS 5.4) Partial String Comparison vulnerability in caddyserver caddy. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 14.3% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 1 · Related 1Timeline
- 23-06-2026PublishedVulnerability first disclosed.
- 26-06-2026Last modifiedVulnerability information updated.
Description
Caddy is an extensible server platform that uses TLS by default. From 2.4.0 until 2.11.3, the authorization layer and the /config traversal layer do not agree on what object the path refers to. In this case, a path authorized for one config object is accepted, but then resolves to a different config object during traversal. This happens because the authorization layer uses string prefix matching and the /config traversal layer parses array indices numerically using strconv.Atoi(). This vulnerability is fixed in 2.11.3.
CVSS metrics
5 scores · 5 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated3.8LowCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:NDiffers
- OSV · DebianEcosystem advisory · calculated3.8LowCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:NDiffers
- OSV · GoEcosystem advisory · calculated5.4MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- NVDNIST3.8LowCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:NDiffers
EPSS trend
Probability
0.24%
Chance of exploitation in the next 30 days
Percentile
14%
Versus all other CVEs
30-day change
+0.07 pp
From 0.17% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundCaddy
Maturity: poc
Weaknesses
CWE · root cause- CWE-187Partial String ComparisonThe product performs a comparison that only examines a portion of a factor before determining whether there is a match, such as a substring, leading to resultant weaknesses.
- CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Affected systems
Caddyserver1 product
- caddy≥ 2.4.0, < 2.11.3
Debian1 product
- caddyAll versions (No fix recorded) | < 2.6.2-12+deb13u1 | < 2.11.4-1
Github.com/caddyserver/caddy1 product
- v2≥ 2.4.0, < 2.11.3
Ubuntu1 product
- caddyAll versions (No fix recorded)
4 vendors · 4 products
References
6 links- github.com/caddyserver/caddy/security/advisories/GHSA-x5w9-xh9r-mvfcX Refsource CONFIRMWEBAdvisoryExploitVendor Advisory
- github.com/caddyserver/caddyPACKAGE