CVE-2026-123613 json
Rustls 0.23.13 before 0.23.45 TLS 1.3 Handshake Encryption Level Bypass
published last mo. modified yesterday also EUVD-2026-119372 , GHSA-2mjx-qc3c-rqvc , RUSTSEC-2026-0285
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 4%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- crates.io rustls 0.23.45
- rustls rustls 0.23.45
- rust-rustls Debian 14 0.23.45+ds-1
debian advisories DEBIAN-CVE-2026-123613
- github.com/rustls/rustls@5046bdf commit
- github.com/golang/go@5046bdf commit
- github.com/rustls/rustls@98456ae commit
- github.com/rustls/rustls#3265 pull request
- github.com/rustls/rustls/releases/tag/v/0.23.45 release
Is CVE-2026-123613 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 FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- yesterday
Exploit prediction
0.16% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 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 |
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| GitHub | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| CNA | 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/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 |
| OSV | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| crates.io | rustls | >=0.23.13, <0.23.45 |
0.23.45 |
Affected products
- rustls rustls
Classification
- Weakness
-
- CWE-20 Improper Input Validation
References
-
github.com
/rustls/rustls/commit/5046bdf8a612b35a2c1a9e168054c1d5c65e7dd7
patch
-
github.com
/rustls/rustls/pull/3265
web
-
github.com
/golang/go/commit/5046bdf8a612b35a2c1a9e168054c1d5c65e7dd7
web
-
github.com
/rustls/rustls/commit/98456aea708a7e3c6151e00ca2d4428e7a58257a
web
-
github.com
/rustls/rustls/security/advisories/GHSA-2mjx-qc3c-rqvc
vendor-advisory, web
-
vulncheck.com
/advisories/rustls-0.23.13-before-0.23.45-tls-1.3-handshake-encryption-level-bypass
third-party-advisory
-
github.com
/rustls/rustls
package
-
github.com
/rustls/rustls/releases/tag/v/0.23.45
web
-
rustsec.org
/advisories/RUSTSEC-2026-0285.html
web, advisory
-
crates.io
/crates/rustls
package
Sources
- CVE List CVE-2026-123613
- GitHub Advisory GHSA-2mjx-qc3c-rqvc
- NVD CVE-2026-123613
- OSV RUSTSEC-2026-0285
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.