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Fencer Vulns
medium 6.1

CVE-2019-19916 json

In Midori Browser 0.5.11 (on Windows 10), Content Security Policy (CSP) is not applied correctly to all parts of multipart content sent wit…

published 2019-12-20 6 y ago modified 2026-06-17 4 mo ago also EUVD-2019-9507

cvss
6.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 75%
public exploits
0
none known

Summary

In Midori Browser 0.5.11 (on Windows 10), Content Security Policy (CSP) is not applied correctly to all parts of multipart content sent with the multipart/x-mixed-replace MIME type. This could result in script running where CSP should have blocked it, allowing for cross-site scripting (XSS) and other attacks when the product renders the content as HTML. Remediating this would also need to consider the polyglot case, e.g., a file that is a valid GIF image and also valid JavaScript.

Exploit prediction

1.57% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/V1n1v131r4/MIME-Confusion-Attack-on-Midori-Browser/blob/master/README.md referenced PoC, tagged "exploit" by a source, unverified
  • portswigger.net https://portswigger.net/research/bypassing-csp-using-polyglot-jpegs referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.