No exploitation reportedFix available

CVE-2018-12391

Q: Is CVE-2018-12391 actively exploited?

Active exploitation of CVE-2018-12391 has not been confirmed. Its EPSS score was 2.1% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2018-12391?

CVE-2018-12391 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2019-02-28
Fixed in63.0
WeaknessCWE-863

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

During HTTP Live Stream playback on Firefox for Android, audio data can be accessed across origins in violation of security policies. Because the problem is in the underlying Android service, this issue is addressed by treating all HLS streams as cross-origin and opaque to access. *Note: this issue only affects Firefox for Android. Desktop versions of Firefox are unaffected.*. This vulnerability affects Firefox < 63, Firefox ESR < 60.3, and Thunderbird < 60.3.

Timeline

dates in UTC

2019-02-2818:29CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2018-12391?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-12391?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Mozilla firefoxversion to verify

Branch	Affected	Fixed in	Source
63.0	< 63.0	63.0	NVD

Mozilla firefox esrversion to verify

Branch	Affected	Fixed in	Source
60.3	< 60.3	60.3	NVD

Mozilla thunderbirdversion to verify

Branch	Affected	Fixed in	Source
60.3	< 60.3	60.3	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Mozilla firefox to 63.0

Advisories and patches

bugzilla.mozilla.orgVendor Advisory
www.mozilla.orgVendor Advisory
www.mozilla.orgVendor Advisory
www.mozilla.orgVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.08.8read 2026-10-23
NVDCVSS 2.09.3read 2026-10-23
NVDweakness (CWE)CWE-863read 2026-10-23
FIRST EPSSEPSS score2.1 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published: 2019-02-28
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2018-12391?

Is CVE-2018-12391 actively exploited?

Active exploitation of CVE-2018-12391 has not been confirmed. Its EPSS score was 2.1% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2018-12391?

CVE-2018-12391 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

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