MISP sachertortephp - CakeResponse::download() HTTP Response Splitting via Unsanitized Filename Enables Stored XSS

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

The CakeResponse::download() method in lib/Cake/Network/CakeResponse.php constructs a Content-Disposition header by directly interpolating a caller-supplied filename into a quoted-string value without sanitization. Two distinct injection vectors exist in the unpatched code. First, if the filename contains C0 control characters (CR or LF), PHP refuses to emit the entire Content-Disposition header, silently dropping the attachment disposition. The response body is then served with its own Content-Type (for example text/html for an .html attachment) and renders inline in the browser on the application origin, creating a stored cross-site scripting condition. The commit message notes this is reachable even when the download_attachments_on_load setting is enabled, meaning a victim merely needs to view a page that triggers the download. Second, a double-quote character in the filename terminates the quoted-string value early, permitting injection of additional Content-Disposition parameters. The affected code path covers all callers of CakeResponse::download(), including attribute downloads, proposal downloads, and restSearch exports. An authenticated user who can create or upload an attachment with a crafted filename (for example through MISP attribute naming or proposal attachment naming) can store the malicious filename. When any other authenticated user views the affected page, the unsanitized filename is reflected into the HTTP response header, resulting in header manipulation and potential execution of arbitrary HTML or JavaScript in the context of the application origin. The security impact is equivalent to a stored cross-site scripting vulnerability, allowing session hijacking, data exfiltration, and unauthorized actions on behalf of the victim.

Source published

6 Oct 2026 18:48:29 UTC

Source modified

7 Oct 2026 16:31:28 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · 8.4 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:H/SI:L/SA:N