Forem: Stored XSS in Admin Abuse Report Rendering

published 2026-08-18 2 mo ago modified 2026-09-18 51 d ago also EUVD-2026-61141

cvss: 6.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 25%
public exploits: 0; none known

Forem is open source software for building communities. In versions before commit 92eacd16a82cf9007ba8e16a2258b42e3b53ca9c, a malicious value submitted through feedback_message[message] is stored without sanitization and rendered in app/views/admin/feedback_messages/_feedback_message.html.erb through raw(feedback_message.message) when offender_id is present. Viewing the abuse report executes arbitrary JavaScript in an administrator's browser and may expose sensitive in-page data, abuse CSRF tokens, or perform administrative actions in the victim's session. The public FeedbackMessagesController accepts the report without authorization and previously permitted a submitted offender_id, making the vulnerable rendering path reachable by an unauthenticated attacker. This issue is fixed in commit 92eacd16a82cf9007ba8e16a2258b42e3b53ca9c

Patch / fix

links 1

github.com/forem/forem@92eacd1 commit

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-08-18)

Exploit prediction

0.32% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N

Affected products

forem forem

Classification

Weakness

CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component
CWE-79 Improper Neutralization of Input During Web Page Generation
CWE-116 Improper Encoding or Escaping of Output

References

Sources

CVE List CVE-2026-61696
NVD CVE-2026-61696

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary