The Mozilla Foundation yesterday released version 68 of its Firefox browser and version 60.8 of Firefox Extended Support Release (ESR), and in doing so patched 21 vulnerabilities between them, two of them critical.

The two most serious flaws consisted of a series of memory bugs found by the browser’s developers and the greater Mozilla community. The first set of bugs, designated CVE-2019-11709, was found in both Firefox and Firefox ESR, while the second group, CVE-2019-11710, was discovered in Firefox only.

“Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code,” the Mozilla Foundation warned in a pair of product security advisories.

Altogether, 21 bugs were fixed in Firefox. Aside from the two critical flaws, there are four flaws rated high in severity, 10 that are considered to be moderate, and five that are low-rated threats. Meanwhile, Firefox ESR was found to contain 10 total bugs: the aforementioned critical one, plus four high-severity threats and five moderate-level threats.