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ApisixApplication · Apache

CVE-2026-49871

CRITICAL · 9.3 CVSS v3.1 Published 2026-06-19
Fix available
A fix is available. Upgrade to 3.17.0 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges

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
Cross-Site Request Forgery (CSRF) vulnerability in the cas-auth plugin under default configurations. This defect allows a remote attacker that manages to send a victim to a webpage controlled by them can cause the victim's browser to become authenticated as a different identity. Actions the victim takes upstream are then attributed to attackers identity. This issue affects Apache APISIX: from 3.0.0 through 3.16.0. Users are recommended to upgrade to version 3.17.0, 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

Cross-Site Request Forgery (CSRF) vulnerability in the cas-auth plugin of Apache APISIX allows remote attackers to trick victims into authenticating as a different identity by sending them to a malicious webpage, enabling identity impersonation.

MitigationUpgrade Apache APISIX to version 3.17.0 or later to obtain the fixed cas-auth plugin.

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
ApisixApplication
Affected:>= 3.0.0, < 3.17.0

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
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

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 APISIX version
    Run 'apisix version' command or check the version file (e.g., /usr/local/apisix/apisix/version or via APISIX dashboard/API)
    Affected if Version is 3.0.0 or higher but lower than 3.17.0
  2. Confirm cas-auth plugin is available
    Check if the cas-auth plugin file exists in the plugins directory (typically /usr/local/apisix/apisix/plugins/ or /opt/apisix/plugins/)
    Affected if The cas-auth.lua plugin file is present in the plugins directory
  3. Verify cas-auth plugin is enabled
    Examine the APISIX configuration file (config.yaml) for the 'plugins' or 'proxy_plugins' list and confirm cas-auth is listed, or query the /v1/plugins endpoint if API access is available
    Affected if cas-auth appears in the enabled plugins list in config.yaml or is accessible via the plugins API

Environment is affected if Apache APISIX version is 3.0.0 through 3.16.x AND the cas-auth plugin is installed and enabled in the configuration.

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 3.17.0 or later
Fixed in 3.17.0
Interim mitigation

Upgrade Apache APISIX to version 3.17.0 or later to obtain the fixed cas-auth plugin.

Recommended fix High confidence

3.17.0

  1. 1. Back up your current Apache APISIX configuration files (e.g., config.yaml,apisix.yaml) and any custom plugin configurations.
  2. 2. Stop the Apache APISIX service to prevent requests during upgrade.
  3. 3. Upgrade Apache APISIX to version 3.17.0. For package-based installations, use your package manager (e.g., apt-get update && apt-get install apisix, or yum install apisix). For containerized deployments, pull the new container image (e.g., docker pull apache/apisix:3.17.0).
  4. 4. Restore your configuration files from the backup taken in step 1.
  5. 5. Start the Apache APISIX service.
  6. 6. Verify the cas-auth plugin is functioning correctly by testing authentication flows.
  7. 7. Confirm the upgrade was successful by checking the APISIX version (e.g., apisix version or via the admin API).
Caveat Review the Apache APISIX 3.17.0 release notes for any configuration or API changes that may affect your deployment

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

Fix this in Apisix Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,328.

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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-2026-49871 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