What is CVE-2019-12278?

CVE-2019-12278 is a medium-severity vulnerability in Opera. CVSS score: 4.3/10. Published 2020-03-12.

How severe is CVE-2019-12278?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Is CVE-2019-12278 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Opera

CVE-2019-12278

Opera through 53 on Android allows Address Bar Spoofing. Characters from several languages are displayed in Right-to-Left order, due to mishandling of several Unicode characters. The rendering mechanism, in conjunction with the "first strong character" concept, may improperly operate on a numerical IP address or an alphabetic string, leading to a spoofed URL.

Published 2020-03-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (55.6th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 55.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Opera — versions 52.1.2517.139570

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

help.opera.com/en/latest/security-and-privacy/ (Vendor Advisory)
medium.com/bugbountywriteup/opera-android-address-bar-spoofing-cve-2019-12278-9… (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2019-12278?: CVE-2019-12278 is a medium-severity vulnerability in Opera. CVSS score: 4.3/10. Published 2020-03-12.
How severe is CVE-2019-12278?: Medium severity. CVSS v3 base score is 4.3 out of 10.
Is CVE-2019-12278 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.