CVE-2023-26049 is a low-severity (CVSS 2.4) Information Exposure vulnerability in org.eclipse.jetty:jetty-server. A fix is available for org.eclipse.jetty:jetty-server — see the affected versions and patch details below.
Cookie parsing of quoted values can exfiltrate values from other cookies in Eclipse Jetty
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-26049 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.eclipse.jetty:jetty-server☕org.eclipse.jetty:jetty-server☕org.eclipse.jetty:jetty-server☕org.eclipse.jetty:jetty-serverReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.eclipse.jetty:jetty-server | all versions | 9.4.51.v20230217org.eclipse.jetty:jetty-server:9.4.51.v20230217 |
| ☕Maven | org.eclipse.jetty:jetty-server | ≥ 10.0.0&&< 10.0.14 | 10.0.14org.eclipse.jetty:jetty-server:10.0.14 |
| ☕Maven | org.eclipse.jetty:jetty-server | ≥ 11.0.0&&< 11.0.14 | 11.0.14org.eclipse.jetty:jetty-server:11.0.14 |
| ☕Maven | org.eclipse.jetty:jetty-server | ≥ 12.0.0alpha0&&< 12.0.0.beta0 | 12.0.0.beta0org.eclipse.jetty:jetty-server:12.0.0.beta0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.eclipse.jetty:jetty-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.eclipse.jetty:jetty-server to 9.4.51.v20230217 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-26049 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-26049 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-26049. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| OCP-Tools-4.12-RHEL-8 | jenkins-0:2.426.3.1706515686-3.el8 | RHSA-2024:0778 |
| Red Hat AMQ Streams 2.5.0 | see advisory | RHSA-2023:5165 |
| Red Hat JBoss Enterprise Application Platform 7.4 for RHEL 8 | eap7-undertow-0:2.2.28-1.SP1_redhat_00001.1.el8eap | RHSA-2023:7638 |
| Red Hat JBoss Enterprise Application Platform 7.4 for RHEL 9 | eap7-undertow-0:2.2.28-1.SP1_redhat_00001.1.el9eap | RHSA-2023:7639 |
| Red Hat JBoss Enterprise Application Platform 7.4 on RHEL 7 | eap7-undertow-0:2.2.28-1.SP1_redhat_00001.1.el7eap | RHSA-2023:7637 |
| Red Hat JBoss Enterprise Application Platform Expansion Pack | jetty-server | RHSA-2024:3385 |
| Red Hat Satellite 6.14 for RHEL 8 | puppetserver-0:7.14.0-1.el8sat | RHSA-2024:0797 |
| Red Hat Single Sign-On 7 | jetty-server | RHSA-2024:0804 |
Frequently Asked Questions
Is CVE-2023-26049 in your dependencies?
O3 Security finds CVE-2023-26049 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.