CVE-2023-26049 Cookie parsing of quoted values can exfiltrate values from other cookies in Eclipse Jetty

What is CVE-2023-26049?

CVE-2023-26049 is a low-severity vulnerability in Debian Debian Linux, published on 18 Apr 2023. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

Official description

Jetty is a java based web server and servlet engine. Nonstandard cookie parsing in Jetty may allow an attacker to smuggle cookies within other cookies, or otherwise perform unintended behavior by tampering with the cookie parsing mechanism. If Jetty sees a cookie VALUE that starts with `"` (double quote), it will continue to read the cookie string until it sees a closing quote -- even if a semicolon is encountered. So, a cookie header such as: `DISPLAY_LANGUAGE="b; JSESSIONID=1337; c=d"` will be parsed as one cookie, with the name DISPLAY_LANGUAGE and a value of b; JSESSIONID=1337; c=d instead of 3 separate cookies. This has security implications because if, say, JSESSIONID is an HttpOnly cookie, and the DISPLAY_LANGUAGE cookie value is rendered on the page, an attacker can smuggle the JSESSIONID cookie into the DISPLAY_LANGUAGE cookie and thereby exfiltrate it. This is significant when an intermediary is enacting some policy based on cookies, so a smuggled cookie can bypass that policy yet still be seen by the Jetty server or its logging system. This issue has been addressed in versions 9.4.51, 10.0.14, 11.0.14, and 12.0.0.beta0 and users are advised to upgrade. There are no known workarounds for this issue.

Weakness: CWE-200

Which versions are affected by CVE-2023-26049?

8 open source packages ship an affected version, including org.eclipse.jetty:jetty-server. It affects 6 products.

Products include Debian Debian Linux, Eclipse Jetty, Netapp Active Iq Unified Manager, Netapp E-Series Santricity Os Controller, Netapp E-Series Santricity Unified Manager, Netapp E-Series Santricity Web Services.

How do I fix CVE-2023-26049?

Upgrade org.eclipse.jetty:jetty-server to a fixed version for your release line: 9.4.51.v20230217, 10.0.14, 11.0.14 or 12.0.0.beta0.

Is CVE-2023-26049 being exploited?

There is no known exploitation of CVE-2023-26049 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as CLEANSTART-2026-CA01896, CLEANSTART-2026-UA75354, CLSA-2026-1787550865, DEBIAN-CVE-2023-26049, GHSA-p26g-97m4-6q7c, UBUNTU-CVE-2023-26049.