rustls 0.23.44 and 0.23.45 contain an information disclosure vulnerability that sends application data buffered before the handshake completes to the client-facing server when Encrypted Client Hello is rejected. Because start_traffic() queues plaintext from ClientConnection::writer() before sending the ech_required alert, the authenticated public_name server receives data intended for the inner server.

Attack Vector Local

Attack Complexity Low

Privileges Required High

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Local

Attack Complexity Low

Privileges Required High

Scope Unchanged

Confidentiality Impact Low

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
rustls rustls unaffected
Version Status Constraints
0.23.44 affected < 0.23.46
0.23.46 unaffected —

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Advisories

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/rustls/rustls/security/advisories/GHSA-vp88-798v-h67f cve-icon cve-icon
https://www.vulncheck.com/advisories/rustls-0.23.44-and-0.23.45-ech-rejection-application-data-disclosure cve-icon cve-icon
History

Sun, 08 Nov 2026 01:45:00 +0000

Type Values Removed Values Added
Description rustls 0.23.44 and 0.23.45 contain an information disclosure vulnerability that sends application data buffered before the handshake completes to the client-facing server when Encrypted Client Hello is rejected. Because start_traffic() queues plaintext from ClientConnection::writer() before sending the ech_required alert, the authenticated public_name server receives data intended for the inner server.
Title rustls 0.23.44 and 0.23.45 ECH Rejection Application Data Disclosure
First Time appeared Rustls Project
Rustls Project rustls
Weaknesses CWE-696
CPEs cpe:2.3:a:rustls_project:rustls:*:*:*:*:*:*:*:*
Vendors & Products Rustls Project
Rustls Project rustls
References
Metrics cvssV3_1

{'score': 2.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N'}

cvssV4_0

{'score': 4.6, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-11-08T01:38:36.873Z

Reserved: 2026-11-06T01:02:39.794Z

Link: CVE-2026-123612

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-11-08T02:16:56.597

Modified: 2026-11-08T02:16:56.597

Link: CVE-2026-123612

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-08T03:00:13Z

Weaknesses