CVE-2026-123612: rustls · Incorrect Behavior Order
Affects rustlsSource CVE Database V5
Not known to be exploited · CVSS 4.6 Medium : upgrade to 0.23.46 when convenient.
Data as of 8 Nov 2026, 01:50 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 4.6 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 2.3 |
- Patch
- Available – fixed in 0.23.46
CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 8 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 7 Nov 2026.
What to do
Upgrade rustls to 0.23.46.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| rustlsrustls | Affected
| Fixed in
|
crates.iorustlspkg:cargo/rustlsOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade rustls to version 0.23.46 or later, where this issue is fixed. No other mitigation is indicated or required.
Description
An information disclosure vulnerability exists in rustls versions 0.23.44 and 0.23.45. When Encrypted Client Hello (ECH) is rejected, application data buffered before handshake completion is sent to the client-facing server instead of being properly isolated. This occurs because start_traffic() queues plaintext data before sending the ech_required alert, causing the authenticated public_name server to receive data intended for the inner server. The issue is fixed in rustls version 0.23.46.