CVE-2017-7559
In Undertow 2.x before 2.0.0.Alpha2, 1.4.x before 1.4.17.Final, and 1.3.x before 1.3.31.Final, it was found that the fix for CVE-2017-2666 was incomplete and invalid characters are still allowed in the query string and path parameters.
Does this matter?
Lower severity and a low EPSS score (1.91%). Track it; it rarely justifies an emergency change on its own.
Description
In Undertow 2.x before 2.0.0.Alpha2, 1.4.x before 1.4.17.Final, and 1.3.x before 1.3.31.Final, it was found that the fix for CVE-2017-2666 was incomplete and invalid characters are still allowed in the query string and path parameters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a different interpretation, to inject data into the HTTP response. By manipulating the HTTP response the attacker could poison a web-cache, perform an XSS attack, or obtain sensitive information from requests other than their own.
- CVSS 3.0
- 6.1 MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 1.91% probability · 80th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-444
- Affected
- redhat/undertow
- Source
- secalert@redhat.com
EPSS 1.9% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://access.redhat.com/errata/RHSA-2017:3454Vendor Advisory
- https://access.redhat.com/errata/RHSA-2017:3455Vendor Advisory
- https://access.redhat.com/errata/RHSA-2017:3456Vendor Advisory
- https://access.redhat.com/errata/RHSA-2017:3458Vendor Advisory
- https://access.redhat.com/errata/RHSA-2018:0002Vendor Advisory
- https://access.redhat.com/errata/RHSA-2018:0003Vendor Advisory
- https://access.redhat.com/errata/RHSA-2018:0004Vendor Advisory
- https://access.redhat.com/errata/RHSA-2018:0005Vendor Advisory
- https://access.redhat.com/errata/RHSA-2018:1322Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-7559Issue Tracking, Vendor Advisory
- https://issues.jboss.org/browse/UNDERTOW-1251Issue Tracking, Vendor Advisory
- https://access.redhat.com/errata/RHSA-2017:3454Vendor Advisory
- https://access.redhat.com/errata/RHSA-2017:3455Vendor Advisory
- https://access.redhat.com/errata/RHSA-2017:3456Vendor Advisory
- https://access.redhat.com/errata/RHSA-2017:3458Vendor Advisory
- https://access.redhat.com/errata/RHSA-2018:0002Vendor Advisory
- https://access.redhat.com/errata/RHSA-2018:0003Vendor Advisory
- https://access.redhat.com/errata/RHSA-2018:0004Vendor Advisory
- https://access.redhat.com/errata/RHSA-2018:0005Vendor Advisory
- https://access.redhat.com/errata/RHSA-2018:1322Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-7559Issue Tracking, Vendor Advisory
- https://issues.jboss.org/browse/UNDERTOW-1251Issue Tracking, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.