CVE-2026-106512: MISP sachertortephp - CakeResponse::download() HTTP Response Splitting via Unsanitized Filename Enables Stored XSS

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.3%

EPSS score, percentile 25.5 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

8.4 High

CVSS v4.0 base score, given by the CNA

What should I do?

The vulnerability is remediated by sanitizing the filename before it is interpolated into the Content-Disposition header. Full textSolution from the CVE record.

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (2)

Which versions are affected?

Affected

• 1c2da20cbe3f and earlier

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Solution (from the CVE record)

The vulnerability is remediated by sanitizing the filename before it is interpolated into the Content-Disposition header. C0 control characters (0x00-0x1F) and DEL (0x7F) are stripped to prevent HTTP response splitting and header suppression. Subsequently, double-quote and backslash characters are escaped using addcslashes per RFC 6266 quoted-string rules to prevent early termination of the quoted value and injection of additional header parameters. Together these two steps ensure the filename remains contained within the intended quoted-string token regardless of its content.

Advisories and patches

• Security patch (Patch)
• Security patch (Patch)

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

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,…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-106512 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 6 Oct 2026.
• The CVE record carries a CVSS v4.0 base score of 8.4 (High), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.3% (percentile 25.5), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.
• The credits in the CVE record name Anthropic (Claude) as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

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

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: CVE List, as of 29 Oct 2026. About the data.

Timeline