What is CVE-2026-5503?

CVE-2026-5503 is a security advisory published by Microsoft Security Response Center (MSRC) with Medium severity. out-of-bounds write in TLSX_EchChangeSNI via attacker-controlled publicName

Which CVE IDs does CVE-2026-5503 cover?

CVE-2026-5503 covers the following CVE IDs: CVE-2026-5503. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

CVE-2026-5503Medium

out-of-bounds write in TLSX_EchChangeSNI via attacker-controlled publicName

Vendor

Microsoft Security Response Center (MSRC)

Published

June 2, 2026

Last Modified

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🔗 CVE IDs covered (1)

CVE-2026-5503 →