CVE-2026-38967
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedCrowCpp Crow through v1.3.1 HTTP is vulnerable to response header injection via unvalidated response header values.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceCrowCpp Crow v1.3.1 and earlier contains a response header injection vulnerability where unvalidated HTTP response header values allow attackers to inject arbitrary headers into HTTP responses, potentially enabling HTTP response splitting, session hijacking, or cross-site scripting attacks.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed CrowCpp Crow versionCheck your project dependencies (package.json, CMakeLists.txt, conanfile.txt, or vcpkg.json) for the Crow library version, or run a dependency scanner against your built applicationAffected if version is 1.3.1 or lower
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Verify custom header handling is in useReview application code for calls that set HTTP response headers (such as crow::response::add_header, res.add_header, or middleware that modifies headers)Affected if application code sets custom response headers using user-supplied or unvalidated input
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Inspect header value sourcesTrace how header values are obtained - look for values derived from URL parameters, query strings, request bodies, cookies, or database fields without sanitizationAffected if header values incorporate any external input without validation
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Check for CRLF or newline characters in header handlingSearch codebase for header-setting logic and verify whether input containing \r\n, \r, or \n is rejected or stripped before being used as header valuesAffected if header values containing newline characters are not explicitly rejected before being passed to the response
You are affected if CrowCpp Crow version 1.3.1 or lower is in use AND your application sets custom HTTP headers using values that originate from untrusted input without validating for CRLF characters.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade CrowCpp Crow to a version beyond v1.3.1 that includes header validation, or implement strict input validation/sanitization on all response header values to reject CRLF sequences and other header injection payloads.
Crow v1.3.2 or later (any version after v1.3.1 that incorporates the fix from PR #1167)
- 1. Identify the current version of CrowCpp Crow being used in your project
- 2. Check the project dependencies or version header files to confirm the exact version
- 3. Obtain the fixed version of Crow (version higher than v1.3.1) from the official repository
- 4. Update the dependency in your project's build system (CMake, conan, vcpkg, or package manager)
- 5. Rebuild and test the application to ensure the upgrade does not break existing functionality
- 6. Verify that response headers are now properly validated before being set
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-38967 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-38967 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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