CVE-2023-26138Public exploitNetwork attack vector

Header injection via unsanitized addHeader values

Published Jul 6, 2023 · Updated Nov 19, 2024

CRLF injection in all Drogon versions allows remote attackers to inject request headers through application-supplied header values. The addHeader function accepts carriage-return and line-feed characters without validation, then serializes them into an outbound HTTP request as new header lines. Exploitation requires a consuming application to place attacker-controlled data in a request header and can cause extra headers or a second request to reach an upstream server.

CVSS severity5.4
Medium
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CRLF injection in all Drogon versions allows remote attackers to inject request headers through application-supplied header values. The addHeader function accepts carriage-return and line-feed characters without validation, then serializes them into an outbound HTTP request as new header lines. Exploitation requires a consuming application to place attacker-controlled data in a request header and can cause extra headers or a second request to reach an upstream server.

The record

CVE
CVE-2023-26138
Published
Jul 6, 2023
Updated
Nov 19, 2024
Vendor
Drogon
Product
Drogon
Classifications
CWE-93, CWE-74, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 6, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 19, 2024Record 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.

  1. Affected versionversion=0 <*

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Drogon · Drogonversion=0 <*

Published CVSS scores

4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
5.4SnykCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-93Improper Neutralization of CRLF Sequences ('CRLF Injection')
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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