CVE-2026-26747 json
A Host Header Poisoning vulnerability exists in Monica 4.1.2 due to improper handling of the HTTP Host header in app/Providers/AppServicePr…
published 2026-02-20 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-7493
- cvss
- 9.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 38%
- public exploits
- 0
- none known
Summary
A Host Header Poisoning vulnerability exists in Monica 4.1.2 due to improper handling of the HTTP Host header in app/Providers/AppServiceProvider.php, combined with the default misconfiguration where the "app.force_url" is not set and default is "false". The application generates absolute URLs (such as those used in password reset emails) using the user-supplied Host header. This allows remote attackers to poison the password reset link sent to a victim,
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 8 mo ago
Exploit prediction
0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/hungnqdz/cve-research/blob/main/CVE-2026-26747.md referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| CNA | 3.1 | 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
Classification
- Weakness
-
- CWE-644 Improper Neutralization of HTTP Headers for Scripting Syntax
References
-
github.com
/hungnqdz/cve-research/blob/main/CVE-2026-26747.md
exploit, vendor-advisory
-
github.com
/monicahq/monica
product
Sources
- CVE List CVE-2026-26747
- NVD CVE-2026-26747
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.