CVE-2019-9792

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

Description

The IonMonkey just-in-time (JIT) compiler can leak an internal JS_OPTIMIZED_OUT magic value to the running script during a bailout. This magic value can then be used by JavaScript to achieve memory corruption, which results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

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-2019-9792

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2019-9792.html

vendor Authored 2026-05-27

Vendor advisory: arch — https://security.archlinux.org/ASA-201903-11

OS impact

OSVersionStatusFixed in
arch archfixed66.0-1
suse slesaffected
debian debiansidfixed66.0-1
debian debianbookwormfixed60.6.0esr-1
debian debianbullseyefixed60.6.0esr-1
debian debianforkyfixed60.6.0esr-1
debian debiantrixiefixed60.6.0esr-1

References

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