CVE-2019-11730

critical
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
9.5

Description

A vulnerability exists where if a user opens a locally saved HTML file, this file can use file: URIs to access other files in the same directory or sub-directories if the names are known or guessed. The Fetch API can then be used to read the contents of any files stored in these directories and they may uploaded to a server. It was demonstrated that in combination with a popular Android messaging app, if a malicious HTML attachment is sent to a user and they opened that attachment in Firefox, due to that app's predictable pattern for locally-saved file names, it is possible to read attachments the victim received from other correspondents. This vulnerability affects Firefox ESR < 60.8, Firefox < 68, and Thunderbird < 60.8.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2019-11730

vendor Authored 2026-05-27

Vendor advisory: arch — https://security.archlinux.org/ASA-201907-4

OS impact

OSVersionStatusFixed in
arch archfixed68.0-1
debian debiansidfixed68.0-1
debian debianbookwormfixed60.8.0esr-1
debian debianbullseyefixed60.8.0esr-1
debian debianforkyfixed60.8.0esr-1
debian debiantrixiefixed60.8.0esr-1

References

Verify integrity in audit chain (admin only). AS-IS.