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Traffic ServerApplication · Apache

CVE-2025-49763

HIGH · 7.5 CVSS v3.1 Published 2025-06-19
Fix available
A fix is available. Upgrade to 9.2.11 / 10.0.6 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
ESI plugin does not have the limit for maximum inclusion depth, and that allows excessive memory consumption if malicious instructions are inserted. Users can use a new setting for the plugin (--max-inclusion-depth) to limit it. This issue affects Apache Traffic Server: from 10.0.0 through 10.0.5, from 9.0.0 through 9.2.10. Users are recommended to upgrade to version 9.2.11 or 10.0.6, 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 confidence

The Apache Traffic Server ESI (Edge Side Includes) plugin lacks a limit on maximum inclusion depth, allowing recursive ESI includes to consume excessive memory. Attackers can craft malicious ESI instructions with deep inclusion chains to cause memory exhaustion and denial of service.

MitigationUpgrade to Apache Traffic Server 9.2.11 or 10.0.6, or configure the new --max-inclusion-depth setting to limit recursion depth and prevent memory exhaustion from malicious ESI includes.

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
Affected:>= 9.0.0, < 9.2.11>= 10.0.0, < 10.0.6

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
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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify Apache Traffic Server version
    Run 'traffic_server -v' or check the installed package version using your system's package manager (e.g., 'rpm -q traffic-server' or 'dpkg -l trafficserver')
    Affected if The installed version falls within >= 9.0.0 and < 9.2.11, or >= 10.0.0 and < 10.0.6
  2. Verify ESI plugin is loaded
    Check the records.config or plugin loading configuration for 'plugin' entries that load the ESI plugin (typically 'plugin.so' or similar ESI-related plugin)
    Affected if The ESI plugin is enabled and loaded in the Traffic Server configuration
  3. Check for max-inclusion-depth setting
    Search configuration files (records.config, esi.config, or plugin config) for the 'max-inclusion-depth' parameter
    Affected if The max-inclusion-depth setting is not configured, meaning unlimited recursion is allowed
  4. Identify ESI include patterns in use
    Review any .esi or configuration files that define ESI include statements (<esi:include>) or check traffic logs for ESI-related requests
    Affected if ESI includes are actively being used, making the server vulnerable to recursive inclusion attacks

A system is affected if it runs Apache Traffic Server version 9.0.0 through 9.2.10 or 10.0.0 through 10.0.5, has the ESI plugin enabled, and does not have a max-inclusion-depth limit configured.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 9.2.11 / 10.0.6 or later
Fixed in 9.2.1110.0.6
Interim mitigation

Upgrade to Apache Traffic Server 9.2.11 or 10.0.6, or configure the new --max-inclusion-depth setting to limit recursion depth and prevent memory exhaustion from malicious ESI includes.

Recommended fix High confidence

9.2.11 or 10.0.6 (depending on current major version)

  1. Identify the current Apache Traffic Server version using 'traffic_server -V' or package manager
  2. Determine the appropriate upgrade path: for major version 9.x upgrade to 9.2.11, for major version 10.x upgrade to 10.0.6
  3. Plan the upgrade during a scheduled maintenance window
  4. Create a backup of the current configuration directory (typically ats.yaml or records.config)
  5. Upgrade the package using the system package manager (e.g., apt-get update && apt-get install traffic-server, or yum update traffic-server)
  6. After upgrade, verify the new version with 'traffic_server -V'
  7. For the ESI plugin, optionally configure the new --max-inclusion-depth parameter to limit inclusion depth as an additional safeguard
  8. Restart the Traffic Server service to apply changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Traffic Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,210
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,936.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-49763 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data