CVE-2026-30852Public exploitNetwork attack vector

Sensitive-data disclosure via placeholder double expansion

Published Mar 7, 2026 · Updated Mar 7, 2026

Information disclosure in Caddy 2.7.5 through 2.11.1 allows remote attackers to read process data through crafted HTTP headers. MatchVarsRE.MatchWithError resolves a request-derived placeholder and then passes the resolved value through repl.ReplaceAll, evaluating injected file, environment, and system placeholders. Exploitation requires a vars_regexp rule over attacker-controlled input and a reflected capture, exposing data readable by the Caddy process without authentication.

CVSS severity7.5
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Caddy 2.7.5 through 2.11.1 allows remote attackers to read process data through crafted HTTP headers. MatchVarsRE.MatchWithError resolves a request-derived placeholder and then passes the resolved value through repl.ReplaceAll, evaluating injected file, environment, and system placeholders. Exploitation requires a vars_regexp rule over attacker-controlled input and a reflected capture, exposing data readable by the Caddy process without authentication.

The record

CVE
CVE-2026-30852
Published
Mar 7, 2026
Updated
Mar 7, 2026
Vendor
Caddy
Product
Caddy
Classifications
CWE-200, CWE-74, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 7, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 2.7.5, < 2.11.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Caddy · Caddyversion=>= 2.7.5, < 2.11.2

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.5GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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