CVE-2026-90823: Stack Overflow (CVSS 9.8)

Description

FatPipe MPVPN, WARP, and IPVPN appliances running the end-of-life firmware version 10.1.2r60p100 contain a stack-based buffer overflow in /usr/sbin/auth_user_pass. An unauthenticated remote attacker with access to the affected management interface can submit a crafted authentication request that reaches an unchecked copy into a fixed-size stack buffer, potentially allowing arbitrary code execution as root. The affected management interface is disabled by default and must be affirmatively enabled by the customer before the endpoint becomes reachable. FatPipe recommends restricting management access to trusted administrative networks and using WAN access control lists to limit access to trusted sources. Customers running the affected end-of-life firmware can contact FatPipe Support for help confirming their firmware version and upgrading to a current supported release at https://www.fatpipeinc.com/support/support, [email protected], or +1 800-724-8521 (option 3).

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CVSS v3.1 Score

9.8

CRITICAL

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

EPSS — Exploit Prediction

0.0068

Probability of exploitation

0.51%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-121 CWE-121

References

Other References

https://www.fatpipeinc.com/support/support https://www.securifera.com/advisories/

Frequently Asked Questions

What is CVE-2026-90823? +

FatPipe MPVPN, WARP, and IPVPN appliances running the end-of-life firmware version 10.1.2r60p100 contain a stack-based buffer overflow in /usr/sbin/auth_user_pass. An unauthenticated remote attacker with access to the affected management interface can submit a crafted authentication request that reaches an unchecked copy into a fixed-size stack buffer, potentially allowing arbitrary code execution as root. The affected management interface is disabled by default and must be affirmatively enabled by the customer before the endpoint becomes reachable. FatPipe recommends restricting management access to trusted administrative networks and using WAN access control lists to limit access to trusted sources. Customers running the affected end-of-life firmware can contact FatPipe Support for help confirming their firmware version and upgrading to a current supported release at https://www.fatpipeinc.com/support/support, [email protected], or +1 800-724-8521 (option 3). It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-90823? +

CVE-2026-90823 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0068, placing it in the 1th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-90823? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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