Cyber Resilience

CVE-2026-53431

Auth Bypass

Published
30 July 2026
Modified
30 July 2026
CVSS Score v4 9.1
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/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
EPSS Score 0.0041 35th percentile
Risk Priority 45 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-53431 is a critical-severity Authentication Bypass by Capture-replay (CWE-294) vulnerability in Erlef (inferred from references). Its CVSS base score is 9.1 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Pass the Ticket (T1550.003); ranked at the 35th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-23 (Session Authenticity) and SC-8 (Transmission Confidentiality and Integrity) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Authentication Bypass by Capture-replay vulnerability in malach-it Boruta allows an attacker who has obtained a previously valid JWT client assertion to authenticate as the issuing OAuth client after the assertion has expired. Boruta accepts JWT-based client authentication (client_secret_jwt and private_key_jwt…

more

token endpoint authentication methods) but never enforces that the assertion's exp claim is in the future. The pre-check helper Boruta.Oauth.Request.Base.check_expiration/1 in lib/boruta/oauth/request/base.ex only verifies that an exp claim is present (it pattern-matches on the existence of the key and returns success), and the Joken token configuration used for signature verification, Boruta.Oauth.Authorization.Client.Token.token_config/0 in lib/boruta/oauth/authorization/client.ex, returns an empty map, so Joken's default exp claim validator is not engaged either. Any attacker who obtains a validly-signed client assertion (for example through logs, reverse proxies, browser tooling, or other observability surfaces) can replay it indefinitely to authenticate as the client and obtain access tokens with that client's privileges. This issue affects boruta: from 2.3.0 before 2.3.7.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1550.003 Pass the Ticket Lateral Movement
Adversaries may “pass the ticket” using stolen Kerberos tickets to move laterally within an environment, bypassing normal system access controls.
T1550.004 Web Session Cookie Lateral Movement
Adversaries can use stolen session cookies to authenticate to web applications and services.
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
T1021 Remote Services Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.002 SMB/Windows Admin Shares Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1040 Network Sniffing Credential Access
Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-41707Shared CWE-294
CVE-2024-12839Shared CWE-294
CVE-2023-0014Shared CWE-294
CVE-2024-43099Shared CWE-294
CVE-2023-6374Shared CWE-294
CVE-2026-34021Shared CWE-294
CVE-2023-2846Shared CWE-294
CVE-2026-51597Shared CWE-294
CVE-2026-20999Shared CWE-294
CVE-2026-20779Shared CWE-294

Affected Assets

Erlef
—
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V10.4.16
  • V10.5.1

Mitigating Controls (NIST 800-53 r5) AI

Session authenticity mechanisms directly stop replay of captured authentication traffic by enforcing freshness or cryptographic binding.

Transmission integrity (with anti-replay) stops captured messages from being accepted as valid later.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

DE.CM-01 partial match
prevents

Network monitoring may detect anomalous replays after the fact but does not prevent the design flaw.

PR.AA-03 partial match
prevents

Strong authentication methods can reduce replay risk but do not inherently address captured messages.

PR.AA-04 partial match
prevents

Protecting and verifying identity assertions prevents replay of captured authentication material.

PR.DS-02 partial match
prevents

Encryption and integrity protections for data-in-transit directly block capture-replay of credentials or tokens.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

mitigates

Network security controls such as encryption and integrity protection reduce the feasibility of capturing and replaying authentication traffic.

prevents

Cryptographic protections (e.g., nonces, timestamps, message authentication codes) make captured authentication messages unusable for replay.

prevents

Application security requirements can mandate replay-resistant authentication designs, but the control itself does not prescribe the technical measures.

prevents

Secure authentication mechanisms directly prevent replay attacks by requiring fresh, non-replayable credentials or tokens.

References