What you need to know
The most specific CDN header can control Cloudflare while a different header continues downstream.
Potentially affected
This concerns the documented Cloudflare response-header precedence.
DSE recommendation
DSE recommends assigning an owner to each cache layer and writing the intended browser, Cloudflare, and other-CDN lifetimes separately.
The most specific CDN header can control Cloudflare while a different header continues downstream.
Source facts
Cloudflare documents Cloudflare-CDN-Cache-Control as more specific than CDN-Cache-Control when both are present. The Cloudflare-specific header is not forwarded downstream; CDN-Cache-Control can be forwarded for other CDNs. Browser Cache TTL modifies Cache-Control rather than these CDN headers, while Edge Cache TTL can override their edge lifetime. Cache Response Rules can introduce an additional higher-precedence directive layer.
Source: Cloudflare — CDN-Cache-Control.
Applicability
This concerns the documented Cloudflare response-header precedence.
DSE recommendation
DSE recommends assigning an owner to each cache layer and writing the intended browser, Cloudflare, and other-CDN lifetimes separately. Prefer explicit headers over unexplained overlapping rules. Inventory any response rules and edge TTL overrides before attributing observed behavior to the origin. Keep sensitive responses out of shared caching regardless of a performance-driven lifetime difference. Use a layer-by-layer policy table with a row for each header producer and override. Ask a reviewer to predict the delivered browser header and the edge freshness interval from that table, then compare both predictions with the same controlled resource before accepting the configuration.
Verification
Inspect the origin response and the response delivered through Cloudflare for a controlled test asset. Confirm which headers are retained downstream and measure revalidation at the intended layers. Compare the effective edge lifetime with matching rules, then test a browser reload independently instead of assuming an edge purge also changes a previously cached browser response.
Official reference
Cloudflare — CDN-Cache-Control. Reviewed October 20, 2026.
Review the official source
Cloudflare — CDN-Cache-Control · Verified October 20, 2026
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