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NVD / CVE Program· CNA mitre

CVE-2012-4144: Opera before 12.01 on Windows and UNIX, and before 11.66 and 12.x before 12.01 on Mac OS X, does not properly escape characters in DOM…

MediumCVSS 4.3 · v2.0—No exploit No fix recorded

Noroxi assessment

Priority: Monitor (action score 17/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1.1% (FIRST EPSS); higher than 68.6% of all records.
  • According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Opera before 12.01 on Windows and UNIX, and before 11.66 and 12.x before 12.01 on Mac OS X, does not properly escape characters in DOM elements, which makes it easier for remote attackers to bypass cross-site scripting (XSS) protection mechanisms via a crafted HTML document.

Published
Aug 6, 2012
Updated
Jun 16, 2026
EPSS
1.1% · 68th percentile

Report tools

JSON

Action score

17

Monitor

Low priority for now.

CVSS
17 / 40 · 4.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.1%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2012-4144

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
operaopera browser
linuxlinux kernel
microsoftwindows
applemac os x

Limit the impact of XSS

This is a cross-site scripting (XSS) vulnerability. A well-configured Content-Security-Policy doesn't fix it, but greatly reduces its impact. Check your site's CSP and other security headers for free.

Check security headers

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • opera opera browserup to 11.65 inclusive
  • opera opera browserup to 12.00 inclusive
  • opera opera browser10.00
  • opera opera browser10.01
  • opera opera browser10.10
  • opera opera browser10.11
  • opera opera browser10.50
  • opera opera browser10.51
+12 more rows
  • opera opera browser10.52
  • opera opera browser10.53
  • opera opera browser10.54
  • opera opera browser10.60
  • opera opera browser10.61
  • opera opera browser10.62
  • opera opera browser10.63
  • opera opera browser11.00
  • opera opera browser11.01
  • opera opera browser11.10
  • opera opera browser11.11
  • opera opera browser11.50

Same product

opera: all records

Other highest-scoring records for the same primary product.

  • CVE-2010-1349Integer overflow in Opera 10.10 through 10.50 allows remote attackers to execute arbitrary code via a large Content-Length value, which…
    46Plan
  • CVE-2011-2628Opera before 11.11 does not properly implement FRAMESET elements, which allows remote attackers to execute arbitrary code or cause a denial…
    44Plan
  • CVE-2012-3561Opera before 11.64 does not properly allocate memory for URL strings, which allows remote attackers to execute arbitrary code or cause a…
    42Plan

Published before and after this one in the same product

  • ← EarlierCVE-2012-4142Aug 6, 2012 · Opera before 12.01 on Windows and UNIX, and before 11.66 and 12.x before 12.01 on Mac OS X, ignores some characters in HTML documents in…
    17Monitor
  • ← EarlierCVE-2012-4143Aug 6, 2012 · Opera before 12.01 on Windows and UNIX, and before 11.66 and 12.x before 12.01 on Mac OS X, allows user-assisted remote attackers to trick…
    27Monitor
  • Later →CVE-2012-4145Aug 6, 2012 · Unspecified vulnerability in Opera before 12.01 on Windows and UNIX, and before 11.66 and 12.x before 12.01 on Mac OS X, has unknown impact…
    41Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate.

Technical details

Attack conditions

    If successful

    Confidentiality
    none
    Integrity
    P · data or configuration can be modified
    Availability
    none
    Attack complexity
    M
    Confidentiality impact
    None
    Integrity impact
    P
    Availability impact
    None

    Weakness class (CWE)

    CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

    CVSS vector

    AV:N/AC:M/Au:N/C:N/I:P/A:N

    nvd-primary

    Root cause

    User content is inserted into the page as HTML. The browser interprets the content as code rather than data.

    The bug in code

    The whole CWE-79 class

    A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

    Vulnerable

    ts
    commentEl.innerHTML = comment.body;

    Fixed

    ts
    commentEl.textContent = comment.body;

    Attack context

    MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

    ATT&CK techniques

    —

    References

    Show all references (4 more)

    Vendor advisories and official records. Exploit/PoC links are deliberately left out.

    All records