CVE-2026-123610

rustls before 0.23.46 Denial of Service via Brotli Certificate Decompression

Published Nov 8, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
Description
rustls before 0.23.46 contains an uncontrolled memory allocation flaw in its optional Brotli certificate decompression, which limits decompressed output size but accepts an input-selected large history window. Malicious peers can send a certificate with a five-byte Brotli header requesting up to 1 GiB before authentication, aborting Brotli-enabled clients or client-authenticating servers whose allocator cannot satisfy the request.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Rustls
Rustls rustls
Vendors & Products Rustls
Rustls rustls
Type Values Removed Values Added
Description rustls before 0.23.46 contains an uncontrolled memory allocation flaw in its optional Brotli certificate decompression, which limits decompressed output size but accepts an input-selected large history window. Malicious peers can send a certificate with a five-byte Brotli header requesting up to 1 GiB before authentication, aborting Brotli-enabled clients or client-authenticating servers whose allocator cannot satisfy the request.
Title rustls before 0.23.46 Denial of Service via Brotli Certificate Decompression
First Time appeared Rustls Project
Rustls Project rustls
Weaknesses CWE-770
CPEs cpe:2.3:a:rustls_project:rustls:*:*:*:*:*:*:*:*
Vendors & Products Rustls Project
Rustls Project rustls
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Nov 9, 2026, 1:52 PM
Reserved
Nov 6, 2026, 1:02 AM
Status
Awaiting Analysis
Published
Nov 8, 2026, 2:16 AM
Modified
Nov 12, 2026, 9:30 PM