How severe is CVE-2026-41873?

CVE-2026-41873 has a CVSS 3.x base score of 9.8, 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 high.

Is CVE-2026-41873 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-41873?

CVE-2026-41873 affects Apache Pony Mail. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-41873?

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-2026-41873 have an EU (EUVD) identifier?

Yes. CVE-2026-41873 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26065.

When was CVE-2026-41873 published?

CVE-2026-41873 was published on 2026-04-28 and last updated on 2026-06-17.

CVE-2026-41873

CVE-2026-41873 is a critical-severity vulnerability in Apache Pony Mail with a CVSS 3.x base score of 9.8. 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-444.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-26065
Weakness: CWE-444
Affected product: Apache Pony Mail
Published: 2026-04-28
Last modified: 2026-06-17

Description

** UNSUPPORTED WHEN ASSIGNED ** Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Pony Mail leading to admin account takeover. This issue affects all versions of the Lua implementation of Pony Mail. There is a Python implementation under development under the name "Pony Mail Foal" that is not affected by this issue, but hasn't been released yet. As the Lua implementation of this project is retired, we do not plan to release a version that fixes this issue. Users are recommended to find an alternative or restrict access to the instance to trusted users. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.

Frequently asked questions

What is CVE-2026-41873?: ** UNSUPPORTED WHEN ASSIGNED ** Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Pony Mail leading to admin account takeover. This issue affects all versions of the Lua implementation of Pony Mail. There is a Python implementation under development under the name "Pony Mail Foal" that is not affected by this issue, but hasn't been released yet. As the Lua implementation of this project is retired, we do not plan to release a version that fixes this issue. Users are recommended to find an alternative or restrict access to the instance to trusted users. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.
How severe is CVE-2026-41873?: CVE-2026-41873 has a CVSS 3.x base score of 9.8, 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 high.
Is CVE-2026-41873 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-41873?: CVE-2026-41873 affects Apache Pony Mail. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-41873?: 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-2026-41873 have an EU (EUVD) identifier?: Yes. CVE-2026-41873 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26065.
When was CVE-2026-41873 published?: CVE-2026-41873 was published on 2026-04-28 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:apache:pony_mail:*:*:*:*:*:*:*:*

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