CVE-2023-26137Public exploitNetwork attack vector

Response splitting via unvalidated header values

Published Jul 6, 2023 · Updated Nov 19, 2024

HTTP response splitting in all Drogon versions allows remote attackers to inject response headers through application-supplied values. HttpResponse addHeader and addCookie accept embedded carriage-return and line-feed bytes and serialize them into the response header block without rejection. Exploitation requires a Drogon application to pass untrusted input into one of these APIs, after which injected headers or content can alter a client's HTTP response.

CVSS severity7.2
High
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP response splitting in all Drogon versions allows remote attackers to inject response headers through application-supplied values. HttpResponse addHeader and addCookie accept embedded carriage-return and line-feed bytes and serialize them into the response header block without rejection. Exploitation requires a Drogon application to pass untrusted input into one of these APIs, after which injected headers or content can alter a client's HTTP response.

The record

CVE
CVE-2023-26137
Published
Jul 6, 2023
Updated
Nov 19, 2024
Vendor
Drogon
Product
Drogon
Classifications
CWE-113, CWE-444
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

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
7.2SnykCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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.

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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-113Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')
CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

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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