How severe is CVE-2026-26747?

CVE-2026-26747 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-26747 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-26747?

CVE-2026-26747 affects Monicahq Monica. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-26747?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-26747 have an EU (EUVD) identifier?

Yes. CVE-2026-26747 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-7493.

When was CVE-2026-26747 published?

CVE-2026-26747 was published on 2026-02-20 and last updated on 2026-06-17.

CVE-2026-26747

CVE-2026-26747 is a critical-severity vulnerability in Monicahq Monica with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-644.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 0% (31st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-7493
Weakness: CWE-644
Affected product: Monicahq Monica
Published: 2026-02-20
Last modified: 2026-06-17

Description

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,

Frequently asked questions

What is CVE-2026-26747?: 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,
How severe is CVE-2026-26747?: CVE-2026-26747 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-26747 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-26747?: CVE-2026-26747 affects Monicahq Monica. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-26747?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-26747 have an EU (EUVD) identifier?: Yes. CVE-2026-26747 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-7493.
When was CVE-2026-26747 published?: CVE-2026-26747 was published on 2026-02-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:monicahq:monica:4.1.2:*:*:*:*:*:*:*

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