CVE-2023-25950
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 · uneditedHTTP request/response smuggling vulnerability in HAProxy version 2.7.0, and 2.6.1 to 2.6.7 allows a remote attacker to alter a legitimate user's request. As a result, the attacker may obtain sensitive information or cause a denial-of-service (DoS) condition.
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 confidenceHTTP request/response smuggling vulnerability in HAProxy allows a remote attacker to craft malicious HTTP requests that bypass the proxy's parsing logic, potentially altering legitimate user requests. This can lead to response splitting, cache poisoning, or session hijacking.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 2.6.1, <= 2.6.7= 2.7.0CVSS 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
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
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 HAProxy versionRun 'haproxy -v' or 'haproxy --version' to display the version informationAffected if The displayed version falls within 2.6.1 through 2.6.7 inclusive, or is exactly 2.7.0
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Confirm HAProxy is running as HTTP proxyCheck the configuration file (commonly /etc/haproxy/haproxy.cfg) for 'frontend' or 'backend' sections containing 'http' or 'mode http' directivesAffected if HAProxy is configured to handle HTTP traffic in proxy mode and the version is vulnerable as identified above
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Verify HTTP parsing is enabledInspect the HAProxy configuration for any 'http-request' or 'http-response' rules, or defaults sections containing 'mode http'Affected if HTTP request parsing rules are defined and the installed version is within the affected range
A user is affected if HAProxy is running with an HTTP proxy configuration and the installed version is 2.6.1-2.6.7 or exactly 2.7.0.
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 HAProxy to version 2.6.8 or later (or a version beyond 2.7.0 with the fix) to resolve the smuggling vulnerability.
HAProxy 2.7.1 or later (or the latest stable 2.8.x release)
- 1. Identify the current HAProxy version using 'haproxy -v' or 'haproxy -vv'
- 2. Plan a maintenance window for the upgrade process
- 3. Back up current HAProxy configuration files (typically /etc/haproxy/haproxy.cfg)
- 4. Download the latest stable HAProxy release from the official repository (www.haproxy.org) or your distribution's package manager
- 5. Upgrade HAProxy using your package manager (e.g., 'apt-get update && apt-get upgrade haproxy' for Debian/Ubuntu, or 'yum update haproxy' for RHEL/CentOS)
- 6. Verify the upgrade was successful by running 'haproxy -v'
- 7. Validate that HAProxy starts correctly and all services are operational
- 8. Test that the HTTP request smuggling issue is resolved by verifying proper HTTP header parsing behavior
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-25950 — 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-2023-25950 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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- Version or environment caveats, and links to real fixes
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