CVE-2021-23253: Opera Mini for Android below 53.1 displays URL left-aligned in the address field

Q: How do I fix CVE-2021-23253?

opera mini: upgrade to 53.1. Exact commands for each OS are on this page.

Q: Is CVE-2021-23253 being exploited?

CVE-2021-23253 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-23253 affect?

CVE-2021-23253 affects opera mini. Severity is medium (CVSS 5.3). Opera Mini for Android below 53.1 displays URL left-aligned in the address field. This allows a malicious attacker to craft a URL with a long domain name, e.g. www.safe.opera.com.attacker.com. With the URL being left-aligned, the user will

Q: How urgent is CVE-2021-23253?

Priority 37/100. Remotely exploitable, no login, no user action

Routine

MEDIUM 5.3REMOTEUPGRADE

CVE-2021-23253 is a medium-severity flaw (CVSS 5.3) affecting opera mini. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Opera Mini for Android below 53.1 displays URL left-aligned in the address field. This allows a malicious attacker to craft a URL with a long domain name, e.g. www.safe.opera.com.attacker.com. With the URL being left-aligned, the user will only see the front part (e.g. www.safe.opera.com…) The exact amount depends on the phone screen size but the attacker can craft a number of different domains and target different phones. Starting with version 5

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 45%)
CISA exploited list	No
Published	2021-01-11
Last modified	2026-06-17

Publisher (CNA): Opera · Vendor: opera

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-01-11 16:15 UTCPublished CVE record published
2026-06-17 03:38 UTCUpdated Record last modified

opera opera mini UPGRADE

Affected: < 53.1

Fixed in: 53.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy opera-mini || rpm -q opera-mini || opera-mini --version

2. UPGRADE to 53.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade opera-mini

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade opera-mini

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-23253?

opera mini: upgrade to 53.1. Exact commands for each OS are on this page.

Is CVE-2021-23253 being exploited?

CVE-2021-23253 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-23253 affect?

CVE-2021-23253 affects opera mini. Severity is medium (CVSS 5.3). Opera Mini for Android below 53.1 displays URL left-aligned in the address field. This allows a malicious attacker to craft a URL with a long domain name, e.g. www.safe.opera.com.attacker.com. With the URL being left-aligned, the user will

How urgent is CVE-2021-23253?

Priority 37/100. Remotely exploitable, no login, no user action

Software pages

Android vulnerabilities

Related CVEs

CVE-2018-16135 MEDIUM 6.5 DOWNGRADE The Opera Mini application 47.1.2249.129326 for Android allows remote attackers to spoof the Location Permissi

References

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