Cyber Resilience

CVE-2025-53102

High

Published: 29 July 2025

Published
29 July 2025
Modified
25 August 2025
KEV Added
Patch
CVSS Score v4 8.2 CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/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
EPSS Score 0.0028 51.8th percentile
Risk Priority 17 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-53102 is a high-severity Session Fixation (CWE-384) vulnerability in Discourse Discourse. Its CVSS base score is 8.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Multi-Factor Authentication Interception (T1111); ranked in the top 48.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Discourse is an open-source community discussion platform. Prior to version 3.4.7 on the `stable` branch and version 3.5.0.beta.8 on the `tests-passed` branch, upon issuing a physical security key for 2FA, the server generates a WebAuthn challenge, which the client signs.…

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The challenge is not cleared from the user’s session after authentication, potentially allowing reuse and increasing security risk. This is fixed in versions 3.4.7 and 3.5.0.beta.8.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1111 Multi-Factor Authentication Interception Credential Access
Adversaries may target multi-factor authentication (MFA) mechanisms, (i.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Vulnerability enables reuse/replay of WebAuthn 2FA challenges not cleared from user sessions (T1111: Multi-Factor Authentication Interception). Exists in public-facing web application Discourse, remotely exploitable without privileges (T1190: Exploit Public-Facing Application).

Affected Assets

discourse
discourse
3.5.0 · ≤ 3.4.6 · ≤ 3.5.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-384

Session termination after a set interval shortens the usable lifetime of a fixed session identifier, making successful exploitation of session fixation more difficult.

addresses: CWE-384

Re-authentication typically forces issuance of a new session, limiting the window for exploitation of a previously fixed session identifier.

addresses: CWE-384

Enforces proper session ID generation and binding, preventing fixation of a known session token.

References