CVE-2026-91839 (CVSS 7.8)

Description

A flaw was found in NetworkManager-fortisslvpn, the FortiSSLVPN plugin for NetworkManager. The nm-fortisslvpn-service improperly handles carriage-return/line-feed (CR/LF) characters in VPN connection profile credentials. A local unprivileged user can exploit this by crafting a malicious VPN profile to inject additional configuration directives. This can lead to arbitrary code execution with root privileges when the crafted VPN connection is activated.

Is your site exposed to CVE-2026-91839?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.8

HIGH

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

EPSS — Exploit Prediction

0.0020

Probability of exploitation

0.10%

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-93 CWE-93

References

Other References

https://access.redhat.com/security/cve/CVE-2026-91839 https://bugzilla.redhat.com/show_bug.cgi?id=2533640 https://gitlab.gnome.org/Archive/NetworkManager-fortisslvpn/-/work_items/80

Frequently Asked Questions

What is CVE-2026-91839? +

A flaw was found in NetworkManager-fortisslvpn, the FortiSSLVPN plugin for NetworkManager. The nm-fortisslvpn-service improperly handles carriage-return/line-feed (CR/LF) characters in VPN connection profile credentials. A local unprivileged user can exploit this by crafting a malicious VPN profile to inject additional configuration directives. This can lead to arbitrary code execution with root privileges when the crafted VPN connection is activated. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-91839? +

CVE-2026-91839 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0020, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-91839? +

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.

Related Vulnerabilities

CVE-2026-44217

sse-channel is an SSE-implementation which can be used to any node.js http request/response stream. Prior to 4.0.1, implementations that allow …

CVE-2026-15429

A privilege escalation vulnerability exists in the HTTP authentication component in Archer VX1800v v1. Improper handling of user-controlled input may …

CVE-2026-48861

Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in elixir-mint Mint allows HTTP Request Splitting and HTTP Request Smuggling. In …

CVE-2025-57804

h2 is a pure-Python implementation of a HTTP/2 protocol stack. Prior to version 4.3.0, an HTTP/2 request splitting vulnerability allows …

CVE-2024-51501

Refit is an automatic type-safe REST library for .NET Core, Xamarin and .NET The various header-related Refit attributes (Header, HeaderCollection …

CVE-2026-127036

Improper neutralization of CRLF sequences ('CRLF injection') vulnerability in ibi WebFOCUS. This issue affects WebFOCUS: 9.1, from 9.2 through 7, …