CVE-2026-49871: Cross-Site Request Forgery (CSRF) vulnerability in the cas-auth plugin under default configurations. This def

This month

CRITICAL 9.3WATCHLISTUPGRADE

CVE-2026-49871 is a critical-severity flaw (CVSS 9.3) affecting apisix. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 up

Why this priority

Critical severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.3 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 72%)
CISA exploited list	No
Weakness	CWE-352
Published	2026-06-19
Last modified	2026-10-26

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-19 14:16 UTCPublished CVE record published
2026-10-26 11:10 UTCUpdated Record last modified

apache apisix UPGRADE

Affected: >= 3.0.0 and < 3.17.0

Fixed in: 3.17.0

Safe to downgrade to: a release before 3.0.0

1. Check installed version

apt-cache policy apisix || rpm -q apisix || apisix --version

2. UPGRADE to 3.17.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade apisix

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade apisix

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 3.0.0 (Debian / Ubuntu)

apt-cache madison apisix sudo apt install apisix=<VERSION_BEFORE_3.0.0> sudo apt-mark hold apisix

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list apisix sudo dnf downgrade apisix-<VERSION_BEFORE_3.0.0> sudo dnf versionlock add apisix

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-49871?

apisix: upgrade to 3.17.0. Exact commands for each OS are on this page.

Is CVE-2026-49871 being exploited?

CVE-2026-49871 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-49871 affect?

CVE-2026-49871 affects apisix. Severity is critical (CVSS 9.3). 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 becom

How urgent is CVE-2026-49871?

Priority 45/100. Critical severity; On your watchlist

Software pages

Apache APISIX vulnerabilities

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References

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