NSS 3.131.1 Patch Addresses Security Flaw CVE-2026-113470 in Mozilla Crypto Library
Developers using Mozilla's Network Security Services should update to version 3.131.1 to resolve a security issue tracked under CVE-2026-113470.
Key points
- Mozilla released NSS version 3.131.1 to fix a security vulnerability.
- The flaw is tracked under the identifier CVE-2026-113470.
- The update was announced by Alan Coopersmith on October 20.
Mozilla has released version 3.131.1 of its Network Security Services library. This update addresses a security vulnerability that affects software relying on this cryptographic component.
What happened
Alan Coopersmith posted an advisory to the oss-security mailing list on October 20. The message announced the availability of NSS version 3.131.1. According to the post, this release contains important security updates for the library.
The advisory links to Mozilla Foundation Security Advisory MFSA2026-112. That document tracks the issue under CVE-2026-113470 for Mozilla products. The update applies to the open-source cryptographic library used by many applications.
Why it matters
Software developers who integrate NSS into their applications are exposed to this risk. The library handles critical security functions such as encryption and authentication. A flaw in these components can compromise the integrity of protected communications.
The availability of a specific version update indicates a confirmed fix. Systems running older versions of NSS remain vulnerable until they are updated. Organizations must verify their dependencies to ensure they are using the patched release.
What to watch
- Check current NSS versions in all development and production environments.
- Review dependency trees for indirect uses of the library.
- Monitor vendor advisories for further details on the flaw.
- Test application stability after applying the 3.131.1 update.
Signals worth monitoring
Security operations teams should monitor for unusual network traffic patterns that might indicate exploitation attempts. Check system logs for unexpected cryptographic errors or failed authentication events. Look for anomalies in certificate validation processes or handshake failures. Investigate any sudden increases in outbound connections from servers that normally handle internal traffic. Verify that logging mechanisms capture detailed SSL/TLS session information. Ensure that intrusion detection systems are tuned to alert on deviations from baseline cryptographic behavior. These indicators help identify potential abuse before significant damage occurs.
What to do and how to stay safe: Mozilla
- Audit your software dependencies to identify all instances of the NSS library.
- Plan an immediate update to version 3.131.1 for all affected systems.
- Test the updated library in a staging environment to ensure compatibility.
- Monitor system logs for any signs of exploitation during the transition.
General security guidance from the Firewall Chronicle newsroom. It is not confirmed advice from the organisations named in this story.
Frequently asked questions
Which CVE identifier is associated with this NSS update?
The vulnerability is tracked under CVE-2026-113470.
When was the NSS 3.131.1 release announced?
The release was announced on October 20.
Who posted the advisory about this update?
Alan Coopersmith posted the advisory on the oss-security mailing list.
