CVE-2026-93579 (CVSS 6.5)

Description

A flaw was found in Netty's HTTP/2 stack. This vulnerability allows a remote attacker to inject prohibited characters, such as NUL, Line Feed, and Carriage Return, into HTTP/2 header field values due to insufficient validation. When these values cross an HTTP/2 to HTTP/1.1 translation boundary, they can be exploited for request smuggling, header injection, or response splitting. This could lead to unauthorized access, data manipulation, or other security bypasses.

Is your site exposed to CVE-2026-93579?

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

CVSS v3.1 Score

6.5

MEDIUM

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

EPSS — Exploit Prediction

0.0090

Probability of exploitation

0.58%

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-1035 CWE-1035

References

Other References

https://access.redhat.com/errata/RHSA-2026:69440 https://access.redhat.com/errata/RHSA-2026:69470 https://access.redhat.com/security/cve/CVE-2026-93579 https://bugzilla.redhat.com/show_bug.cgi?id=2536970

Frequently Asked Questions

What is CVE-2026-93579? +

A flaw was found in Netty's HTTP/2 stack. This vulnerability allows a remote attacker to inject prohibited characters, such as NUL, Line Feed, and Carriage Return, into HTTP/2 header field values due to insufficient validation. When these values cross an HTTP/2 to HTTP/1.1 translation boundary, they can be exploited for request smuggling, header injection, or response splitting. This could lead to unauthorized access, data manipulation, or other security bypasses. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-93579? +

CVE-2026-93579 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0090, placing it in the 1th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-93579? +

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-2026-93558 7.5

A flaw was found in Netty's WebSocketServerExtensionHandler. A remote, unauthenticated attacker can exploit this vulnerability by using HTTP/1.1 pipelining to …

CVE-2026-93564 7.5

A flaw was found in Netty. A reference-count leak in the HAProxy PROXY-v2 message decoder allows a remote, unauthenticated attacker …

CVE-2026-93494 7.5

A flaw was found in Netty's StompSubframeDecoder component. A remote attacker can exploit this vulnerability by sending a specially crafted …

CVE-2026-93575 7.5

A flaw was found in Netty's MqttDecoder. An unauthenticated remote attacker can exploit this vulnerability by sending a specially crafted …

CVE-2026-93563 7.5

A flaw was found in Netty's `SmtpResponseDecoder` component. A remote attacker, acting as a malicious or man-in-the-middle (MITM) SMTP server, …

CVE-2026-93565 7.5

A flaw was found in Netty RtspDecoder. The `RtspMethods.valueOf()` function incorrectly strips trailing control bytes from method tokens in Real-Time …

CVE-2026-93579