MEDIUMVulnerability

CVE-2026-72721

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Onebox::DomainChecker.is_blocked? compares hostnames and SiteSetting.blocked_onebox_domains entries case-sensitively, allowing an attacker to bypass configured Onebox domain restrictions by changing character casing in a redirect target hostname. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0.

Properties

severity
MEDIUM
score
5.3
epss_score
0.00429
cve_id
CVE-2026-72721
vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
published_at
2026-08-10T16:19:49.360
last_modified
2026-09-08T20:54:37.790
epss_percentile
0.35987

Related Entities (3)

ENRICHED_BY (1)

[Source]FIRST EPSS

HAS_WEAKNESS (1)

[Weakness]Improper Handling of Case Sensitivity

DESCRIBED_BY (1)

[Source]NVD

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CVE-2026-72721 — Ninja Signal Threat Intelligence | Ninja Signal