DirectorySecurity AdvisoriesPricing
/
Sign in
Security Advisories

CVE-2025-5270

NVD

https://nvd.nist.gov/vuln/detail/CVE-2025-5270

Severity

7.5

High

CVSS V3

Eliminate CVEs with Chainguard hardened images

Build, ship, and run secure software with minimal, hardened container images — rebuilt from source daily and guarded under our industry-leading remediation SLA.

Start for free

Description

In certain cases, SNI could have been sent unencrypted even when encrypted DNS was enabled. This vulnerability affects Firefox < 139 and Thunderbird < 139.

References

  • https://nvd.nist.gov/vuln/detail/CVE-2025-5270
  • https://github.com/advisories/GHSA-hf6r-227w-qwf9
  • https://www.mozilla.org/security/advisories/mfsa2025-42/
  • https://www.mozilla.org/security/advisories/mfsa2025-45/
  • https://bugzilla.mozilla.org/show_bug.cgi?id=1910298

Affected packages

The trusted source for open source

Talk to an expert
PrivacyTerms

Product

Chainguard ContainersChainguard LibrariesChainguard VMsIntegrationsPricing

Solutions

FedRAMPPCI DSSCMMC 2.0Golden ImagesCVE RemediationPublic Sector

Customers

Customer StoriesChainguard Reviews

Resources

Events & WebinarsSupply Chain Security 101Chainguard CoursesDocumentationTrust CenterChainguard Slack Community

Company

About UsBlogPartnersNewsroomCareersLegal
© 2026 Chainguard, Inc. All Rights Reserved.
Chainguard® and the Chainguard logo are registered trademarks of Chainguard, Inc. in the United States and/or other countries.
The other respective trademarks mentioned on this page are owned by the respective companies and use of them does not imply any affiliation or endorsement.