Context
Change Type: Announcement
Product area: Platform services
Component: REST API
Deployed at: eu.latest.cumulocity.com, apj.cumulocity.com, jp.cumulocity.com, cumulocity.com, us.cumulocity.com
Technical details
Build artifact: cumulocity (2026.208.0)
Internal ID: MTM-67152
Description
The Jetty servlet container has been updated from version 11 to version 12. As a result, the Expires
attribute of the Set-Cookie header is now serialized using the standard RFC 1123 date format with spaces
(for example, Fri, 10 Jul 2026 07:30:15 GMT) instead of the legacy dash-separated Netscape cookie-date
format (Fri, 10-Jul-2026 07:30:15 GMT).
To facilitate the adaptation of customer integrations, the platform will keep backwards compatibility and
continue returning the legacy dash-separated format until the end of the year. Starting next year
and with the 2027 yearly release, the backwards compatibility patch will be removed
and the Expires date will be returned in accordance with the standards described in the RFC.
Use this transition period to make sure your integrations support the RFC date format. The Apache HTTP Client
is a known example of a library that fails to parse the standard RFC 1123 Expires format and rejects the
affected cookies - this particular incompatibility is tracked in the Jetty project issue #12771.
Other clients with strict cookie parsers might be affected as well.
For details on the standardized date formats, refer to the
HTTP-date format in RFC 9110 and the
cookie Expires attribute in RFC 6265.