CVE-2019-11730

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.

Published: 2019-07-23 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-11730 is rated Moderate Risk (61.9/100): CVSS Medium severity, with high exploitation likelihood (EPSS 20.27%, 97th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +1.86% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2019-11730

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 18.41% 20.27% +1.86%
2 2026-05-30 19.42% 18.41% -1.01%
3 2026-05-08 — 19.42% —

Full EPSS history (28 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-11730

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2019-11730

OS Trackers for CVE-2019-11730

vendor priority summary link
alpine medium CVE-2019-11730: 1 source package rows (firefox-esr); 7 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 0. https://security.alpinelinux.org/vuln/CVE-2019-11730
debian not yet assigned CVE-2019-11730 not yet assigned priority: Debian including 3 source packages (firefox, firefox-esr, thunderbird), 11 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 11. https://security-tracker.debian.org/tracker/CVE-2019-11730
gentoo normal CVE-2019-11730: 2 GLSA(s) (201908-12, 201908-20), 4 atom(s) (mail-client/thunderbird, mail-client/thunderbird-bin, www-client/firefox, www-client/firefox-bin); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2019-11730
redhat medium — https://access.redhat.com/security/cve/CVE-2019-11730
ubuntu medium CVE-2019-11730 medium priority: Ubuntu including 5 source packages (firefox, mozjs38, mozjs52, mozjs60, thunderbird), 80 status rows across 16 suites (bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, trusty, upstream, xenial): DNE 37, released 30, ignored 13. https://ubuntu.com/security/CVE-2019-11730

Affected software / configurations for CVE-2019-11730

Vendor Product Version Raw CPE
mozilla firefox < 68.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla firefox_esr < 60.8 cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
mozilla thunderbird < 60.8 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
opensuse leap 15.0 cpe:2.3:o:opensuse:leap:15.0:*:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
suse package_hub — cpe:2.3:a:suse:package_hub:-:*:*:*:*:*:*:*

References for CVE-2019-11730

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00055.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00058.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00073.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00009.html Mailing List Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00010.html Mailing List Third Party Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1558299 Issue Tracking Permissions Required
https://lists.debian.org/debian-lts-announce/2019/08/msg00001.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/08/msg00002.html Mailing List Third Party Advisory
https://security.gentoo.org/glsa/201908-12 Third Party Advisory
https://security.gentoo.org/glsa/201908-20 Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2019-21/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-22/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2019-23/ Vendor Advisory
cvelogic Threat Intelligence