Traffic ServerApplication · Apache
CVE-2023-39456
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 · uneditedImproper Input Validation vulnerability in Apache Traffic Server with malformed HTTP/2 frames.This issue affects Apache Traffic Server: from 9.0.0 through 9.2.2. Users are recommended to upgrade to version 9.2.3, which fixes the issue.
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 · high confidenceImproper input validation vulnerability in Apache Traffic Server allows processing of malformed HTTP/2 frames, potentially leading to unexpected behavior or denial of service. The vulnerability exists in the HTTP/2 frame handling code within versions 9.0.0 through 9.2.2.
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
Traffic ServerApplication
>= 9.0.0, < 9.2.3
FedoraOperating system
= 37= 38CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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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Determine installed Apache Traffic Server versionRun 'traffic_server -V' or check package manager output (e.g., 'rpm -q traffic-server' on RHEL/Fedora, 'dpkg -l traffic-server' on Debian)Affected if Version is 9.0.0 through 9.2.2 (or any version < 9.2.3)
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Verify HTTP/2 protocol support is enabledCheck the records.config file (typically in /etc/traffic_server/ or /etc/trafficserver/) for 'proxy.config.http2.enabled' settingAffected if HTTP/2 is enabled (value set to 1 or true) AND version is in affected range
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Confirm traffic_server process is running and handling HTTP/2 trafficRun 'traffic_ctl server start' to check server status, and review logs in /var/log/trafficserver/ for HTTP/2 frame processing activityAffected if Server is running with HTTP/2 support active and version is vulnerable
You are affected if Apache Traffic Server version is 9.0.0 through 9.2.2 and HTTP/2 protocol handling is enabled in your configuration.
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 · scoped9.2.3
Upgrade to Apache Traffic Server version 9.2.3 or later to remediate this improper input validation issue in HTTP/2 frame processing.
9.2.3
- 1. Stop the Apache Traffic Server service
- 2. Back up the current configuration and data directories
- 3. Upgrade Apache Traffic Server to version 9.2.3 or later
- 4. Verify the installation and configuration integrity
- 5. Start the Apache Traffic Server service
- 6. Verify the server is processing HTTP/2 requests correctly
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Traffic Server
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing6.0 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 $4,128.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-39456 — 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-2023-39456 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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