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CVE-2026-123613

Rustls 0.23.13 before 0.23.45 TLS 1.3 Handshake Encryption Level Bypass

CVSS score

6.9

EPSS probability

—

Risk score

0.7

Published

1 h ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Official patch verified

Etkilenen ürün ve sürüm için yayımlanan güvenlik güncellemesini uygulayın.

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Vulnerability description

DayBreach AI Explanation

Verified against sources

CVE-2026-123613: Rustls TLS 1.3 Handshake Encryption Level Bypass Vulnerability

Sources read

1

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

Rustls versions accept TLS 1.3 handshake messages at the wrong encryption level because RFC 8446 record-boundary alignment is not enforced.

Why does it matter?

An attacker can force the system to accept unencrypted handshake messages, potentially weakening encryption mechanisms and leading to confidentiality breaches.

What should be done?

  • Update the rustls package
  • Follow vendor advisory guidelines
  • Apply the provided patch commits
Chain of evidence and sources2 verified claims

Rustls 0.23.13 ile 0.23.45 sürümleri arasında, Deframer::aligned fonksiyonunun RFC 8446 kayıt sınırı hizalamasını uygulamaması nedeniyle zafiyet oluşur.

S0 · daybreach-canonicalS1 · cvelist

Saldırganlar düz metin halindeki EncryptedExtensions mesajını ServerHello ile paketleyebilir ve bu mesajlar şifrelenmeden kabul edilir.

S0 · daybreach-canonicalS1 · cvelist
Show the technical text from the sources

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.

CVSS vector: 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

CWE: CWE-20

This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-123613 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1rustlsrustls View
Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
6.9CVSS V4_0MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NCVE CNA
6.9CVSS V40MEDIUMCVSS: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:XNVD
5.3CVSS V3_1MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NCVE CNA
5.3CVSS V31MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NNVD

Patch and Remediation Guide

Solution & Remediation Advisory

Patch verified

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

cvelist

Patch Commit

Open source
reference

Patch Commit

Open source
Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Apply the official update named in the evidence only to the matching product and version.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-123613 is associated with the following CWEs:

CWE-20: Improper Input Validation

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-123613 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsGerekmiyor
UserGerekmiyor

Official Sources and Advisories

GitHub Security Advisory (GHSA-2mjx-qc3c-rqvc)vendor-advisoryPatch CommitpatchVulnCheck Advisory: Rustls 0.23.13 before 0.23.45 TLS 1.3 Handshake Encryption Level Bypassvendor-advisory

CVSS Vector Radar Chart

6.9 / 10
Attack VectorNetworkComplexityLowPrivilegesNoneUser Interact.NoneConfidentialityLowIntegrityNoneAvailabilityNone

Vulnerability Scoring Details

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
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone required
User InteractionNone required
Confidentiality (Gizlilik)Low
Integrity (Bütünlük)None
Availability (Erişilebilirlik)None

Yama doğrulandı

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

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Weakness Type (CWE & CAPEC)

CWE-20

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