CVE-2016-5261: Integer Overflow

Published Aug 5, 2016
·
Updated

An integer overflow error in WebSockets during data buffering on incoming packets resulting in attacker controlled data being written at a known offset in the allocated buffer.

Other sources

Integer overflow in the WebSocketChannel class in the WebSockets subsystem in Mozilla Firefox before 48.0 and Firefox ESR < 45.4 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via crafted packets that trigger incorrect buffer-resize operations during buffering.

Launchpad

Affected Software

4 affected componentsFixes available
Mozilla Firefox<=47.0.1
Mozilla Firefox ESR<45.4
45.4
debian/firefox
137.0.1-1
debian/firefox-esr
115.14.0esr-1~deb11u1128.9.0esr-1~deb11u1128.8.0esr-1~deb12u1128.9.0esr-1~deb12u1128.9.0esr-2

Event History

Aug 5, 2016
CVE Published
via MITRE·01:00 AM
Data Sourced
via MITRE·01:00 AM
Description
Jan 11, 2024
Data Sourced
via Launchpad·10:19 PM
Description
Sep 16, 2024
Data Sourced
via Ubuntu·01:15 AM
RemedyDescriptionSeverityAffected Software
Mar 27, 2025
Data Sourced
via Debian·03:29 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

1

What is CVE-2016-5261?

CVE-2016-5261 is an integer overflow error in WebSockets during data buffering on incoming packets resulting in arbitrary code execution or denial of service in Mozilla Firefox before version 48.0 and Firefox ESR before version 45.4.

2

How does CVE-2016-5261 affect Firefox?

CVE-2016-5261 affects Mozilla Firefox versions before 48.0 and Firefox ESR versions before 45.4, allowing remote attackers to execute arbitrary code or cause a denial of service through crafted packets.

3

What is the severity of CVE-2016-5261?

CVE-2016-5261 has a severity rating of 8.8 (High).

4

How can I fix CVE-2016-5261 in Mozilla Firefox?

To fix CVE-2016-5261 in Mozilla Firefox, update to version 48.0 or later for regular Firefox, or version 45.4 or later for Firefox ESR.

5

Where can I find more information about CVE-2016-5261?

You can find more information about CVE-2016-5261 in the following references: [Link 1](https://bugzilla.mozilla.org/show_bug.cgi?id=1287266), [Link 2](https://www.mozilla.org/en-US/security/advisories/mfsa2016-86/), [Link 3](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-5261).

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203