Rustls 0.23.13 before 0.23.45 TLS 1.3 Handshake Encryption Level Bypass
Historical advisory recorded 8 Nov 2026 03:06:35 UTC. Read the latest advisory.
cve-program · CVE-2026-123613
PublishedRustls from 0.23.13 before 0.23.45 accepts TLS 1.3 handshake messages at the wrong encryption level when they follow a key-changing message in the same record, because Deframer::aligned does not enforce RFC 8446 record-boundary alignment. A peer or on-path attacker can pack a plaintext EncryptedExtensions with the ServerHello, which rustls accepts unencrypted.
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cve-program · CVE-2026-123613
PublishedRustls 0.23.13 before 0.23.45 TLS 1.3 Handshake Encryption Level Bypass
Rustls from 0.23.13 before 0.23.45 accepts TLS 1.3 handshake messages at the wrong encryption level when they follow a key-changing message in the same record, because Deframer::aligned does not enforce RFC 8446 record-boundary alignment. A peer or on-path attacker can pack a plaintext EncryptedExtensions with the ServerHello, which rustls accepts unencrypted.
- Source published
- 8 Nov 2026 01:38:37 UTC
- Source modified
- 8 Nov 2026 01:38:37 UTC
- Saved here
- 8 Nov 2026 03:06:35 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 4.0 · 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS 3.1 · 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N