🛡️ CVE-2026-53963 — discourse

🔴 CVSS 9.5 — Critical ✅ No Known Exploit CWE-79 OSV
9.5
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Discourse: Stored-XSS in 2FA delete confirmation modal

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a malicious second factor name on an attacker-controlled account was not escaped in the delete confirmation dialog, allowing stored cross-site scripting when an administrator impersonated that account. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability none.

Weakness class

CVE-2026-53963 is classified as CWE-79: Cross-site Scripting (XSS). User-supplied data is written into a page without escaping, so attacker script runs in the browser of anyone who views it.

Affected software

CVE-2026-53963 is recorded against 1 package.

  • discourse

Timeline and source

Published on 15 July 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from OSV.

References

github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
github.com (Web)
nvd.nist.gov (Web)

Details

Severity CRITICAL
CVSS Score 9.5
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
CWE CWE-79
Public Exploit ✅ No
Source OSV
Published 2026-07-15
Updated 2026-08-12
Modified 2026-07-15

Affected Packages

Software From version Fixed in
discourse

Similar Threats

Exploit Protection

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