What is CVE-2026-66339?

CVE-2026-66339 is a security advisory published by Microsoft Security Response Center (MSRC) with Medium severity. Libsoup: libsoup: proxy credentials leak to destination server via proxy-authorization header in connect tunnels

Which CVE IDs does CVE-2026-66339 cover?

CVE-2026-66339 covers the following CVE IDs: CVE-2026-66339. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-66339?

CVE-2026-66339 has a CVSS v3 base score of 6.5, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-66339?

CVE-2026-66339 affects 2 products, including: azl3 libsoup 3.4.4-16 on Azure Linux 3.0; azl3 libsoup 3.4.4-17 on Azure Linux 3.0.

CVE-2026-66339MediumCVSS 6.5

Libsoup: libsoup: proxy credentials leak to destination server via proxy-authorization header in connect tunnels

Vendor

Microsoft Security Response Center (MSRC)

Published

August 7, 2026

Last Modified

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🔗 CVE IDs covered (1)

CVE-2026-66339 →

🎯 Affected products2

azl3 libsoup 3.4.4-16 on Azure Linux 3.0
azl3 libsoup 3.4.4-17 on Azure Linux 3.0

✅ Remediation

KBRelease Notes (Security Update)

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66339
referencehttps://learn.microsoft.com/en-us/azure/azure-linux/tutorial-azure-linux-upgrade