Is CVE-2026-23845 in the CISA KEV catalog?

No. CVE-2026-23845 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-23845?

CVE-2026-23845 has a CVSS v3 base score of 5.8 (MEDIUM).

What is the EPSS score for CVE-2026-23845?

CVE-2026-23845 has an EPSS score of 0.40% (32th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-23845?

Upgrade mailpit to 1.28.3 or later.

CVE & CISA-KEV Catalog

CVE-2026-23845

MEDIUM

5.8

CVSS v3

NVD

Description

Mailpit is an email testing tool and API for developers. Versions prior to 1.28.3 are vulnerable to Server-Side Request Forgery (SSRF) via HTML Check CSS Download. The HTML Check feature (`/api/v1/message/{ID}/html-check`) is designed to analyze HTML emails for compatibility. During this process, the `inlineRemoteCSS()` function automatically downloads CSS files from external `<link rel="stylesheet" href="...">` tags to inline them for testing. Version 1.28.3 fixes the issue.

CWE-918Server-Side Request Forgery (SSRF)

How to fix

Remediation Available

mailpitNVD

Affected:< 1.28.3Fixed in:1.28.3CVE-2026-23845derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeChanged

Impact

ConfidentialityLow

IntegrityNone

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

Exploit Intelligence

0.40%probability of exploitation in 30 days

32ndpercentile

Low risk: more likely to be exploited than 32% of all known CVEs.

References

Patch1

github.com

Exploit1

github.com

Release Notes1

github.com

Related Vulnerabilities

Other CWE-918 (Server-Side Request Forgery (SSRF)) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2024-21893	High	8.2	100%	KEV + Ransom	-
CVE-2021-40438	Critical	9.0	100%	KEV	Fix
CVE-2021-34473	Critical	9.1	100%	KEV + Ransom	Fix
CVE-2021-26855	Critical	9.1	100%	KEV + Ransom	Fix
CVE-2021-21985	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2022-41040	High	8.8	100%	KEV + Ransom	Fix

Embed a live status badge for CVE-2026-23845

Markdown

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HTML

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-02-05.