CVE-2019-9813

Exp

Incorrect handling of __proto__ mutations may lead to type confusion in IonMonkey JIT code and can be leveraged for arbitrary memory read and write. This vulnerability affects Firefox < 66.0.1, Firefox ESR < 60.6.1, and Thunderbird < 60.6.1.

Published: 2019-04-26 Last update: 2025-11-25 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2019-9813 is rated High Exploit Risk (79.5/100): CVSS High severity, with high exploitation likelihood (EPSS 46.67%, 98th percentile). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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

Public exploit references (Exploit-DB) for CVE-2019-9813

EDB-ID Source Kind Published Link
46646 exploit_db edb 2019-04-03 Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2019-9813

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 2026-03-13 51.51% 46.67% -4.84%
2 2026-02-09 51.92% 51.51% -0.41%
3 2026-02-07 — 51.92% —

Full EPSS history (27 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-9813

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H 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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P 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:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2019-9813

OS Trackers for CVE-2019-9813

vendor priority summary link
alpine — CVE-2019-9813: 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-2019-9813
debian not yet assigned CVE-2019-9813 not yet assigned priority: Debian including 2 source packages (firefox, firefox-esr), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2019-9813
gentoo normal CVE-2019-9813: 1 GLSA(s) (201904-07), 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-2019-9813
redhat critical — https://access.redhat.com/security/cve/CVE-2019-9813
suse medium CVE-2019-9813 severity moderate: SUSE including 83 source package names (MozillaFirefox-102.11.0-150200.152.87.1, MozillaFirefox-115.10.0-150200.152.134.1, …), 168 product×package rows across 52 product lines (SUSE Enterprise Storage 4, SUSE Liberty Linux 7, … (52 product lines)): Fixed 168. https://www.suse.com/security/cve/CVE-2019-9813/
ubuntu medium CVE-2019-9813 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 35, released 32, ignored 13. https://ubuntu.com/security/CVE-2019-9813

Affected software / configurations for CVE-2019-9813

Vendor Product Version Raw CPE
mozilla firefox < 60.6.1 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla firefox < 66.0.1 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla thunderbird < 60.6.1 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

References for CVE-2019-9813

cvelogic Threat Intelligence