CVE-2026-123612 json
rustls 0.23.44 and 0.23.45 ECH Rejection Application Data Disclosure
published 28d ago modified 3d ago also EUVD-2026-119371 , GHSA-vp88-798v-h67f , RUSTSEC-2026-0347
- cvss
- 2.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.1%
- EPSS 0.1% chance of exploitation in 30 days, percentile 1%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- crates.io rustls 0.23.46, 0.24.0-dev.2
- rustls rustls 0.23.46
- github.com/rustls/rustls@2bd5c0c commit
- github.com/rustls/rustls@4de14a5 commit
- github.com/rustls/rustls@7dcbe4c commit
- github.com/rustls/rustls#3300 pull request
- github.com/rustls/rustls#3354 pull request
- github.com/rustls/rustls/releases/tag/v/0.23.46 release
Is CVE-2026-123612 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.11% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 4.6 | 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 |
| CNA | 3.1 | 2.3 | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N |
| GitHub | 3.1 | 2.3 | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N |
| CNA | 4.0 | 4.6 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 2.3 | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N |
| OSV | 3.1 | 2.3 | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| crates.io | rustls | >=0.23.44, <0.23.46 >=0.24.0-dev.1, <0.24.0-dev.2 |
0.23.46 0.24.0-dev.2 |
Affected products
- rustls rustls
Classification
References
-
github.com
/rustls/rustls/pull/3300
web
-
github.com
/rustls/rustls/pull/3354
web
-
github.com
/rustls/rustls/commit/2bd5c0cefabb2c5fd4100383a736d59f9671b9b4
web
-
github.com
/rustls/rustls/commit/4de14a508fbfa2273203ec17d9dfdd0fbd29e8d1
web
-
github.com
/rustls/rustls/commit/7dcbe4c1ae12185237d22e9197583329630a2014
web
-
github.com
/rustls/rustls/security/advisories/GHSA-vp88-798v-h67f
vendor-advisory, web
-
vulncheck.com
/advisories/rustls-0.23.44-and-0.23.45-ech-rejection-application-data-disclosure
third-party-advisory
-
github.com
/rustls/rustls
package
-
github.com
/rustls/rustls/releases/tag/v/0.23.46
web
-
rustsec.org
/advisories/RUSTSEC-2026-0347.html
web, advisory
-
crates.io
/crates/rustls
package
Sources
- CVE List CVE-2026-123612
- GitHub Advisory GHSA-vp88-798v-h67f
- NVD CVE-2026-123612
- OSV RUSTSEC-2026-0347
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.