CVE-2026-30913 json
flarum/nickname: Display name injection in notification emails (autolink & markdown)
published 2026-03-09 8 mo ago modified 2026-06-17 4 mo ago also GHSA-3c4m-j3g4-hh25 , EUVD-2026-10422
- cvss
- 4.6
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 9%
- public exploits
- 0
- none known
Summary
Flarum is open-source forum software. When the flarum/nicknames extension is enabled, a registered user can set their nickname to a string that email clients interpret as a hyperlink. The nickname is inserted verbatim into plain-text notification emails, and recipients may be misled into visiting attacker-controlled domains.
Patch / fix
- packagist flarum/nicknames 1.8.3
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 8 mo ago
Exploit prediction
0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/flarum/framework/security/advisories/GHSA-3c4m-j3g4-hh25 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.6 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N |
| GitHub | 3.1 | 4.6 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | flarum/nicknames | <1.8.3 |
1.8.3 |
Affected products
- flarum nicknames
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/flarum/nicknames/commit/4dde99729abdce8f6e2a7437c86e38735fdcca28
web
-
github.com
/flarum/framework/security/advisories/GHSA-3c4m-j3g4-hh25
exploit, web
-
github.com
/flarum/nicknames/releases/tag/v1.8.
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-30913
advisory
-
github.com
/flarum/framework
package
-
github.com
/flarum/nicknames/releases/tag/v1.8.3
web
Sources
- CVE List CVE-2026-30913
- GitHub Advisory GHSA-3c4m-j3g4-hh25
- NVD CVE-2026-30913
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