CVE-2026-48824
Mailpit: Sibling-endpoint memory-exhaustion DoS via unbounded JSON body on /api/v1/messages, /api/v1/tags, and /api/v1/message/{id}/release (incomplete fix of GHSA-fpxj-m5q8-fphw)
Description
Mailpit is an email testing tool and API for developers. Prior to version 1.30.1, the fix for GHSA-fpxj-m5q8-fphw (CVE-2026-45710, "Mailpit: Set a default 50MB p/m limit to prevent DoS via unlimited SMTP DATA and /api/v1/send body sizes") wrapped only `POST /api/v1/send` with `http.MaxBytesReader`. The four other Mailpit JSON-body API endpoints `PUT /api/v1/messages` (SetReadStatus), `DELETE /api/v1/messages` (DeleteMessages), `PUT /api/v1/tags` (SetMessageTags), and `POST /api/v1/message/{id}/release` (ReleaseMessage) still call `json.NewDecoder(r.Body)` directly with no body-size cap and remain reachable unauthenticated in the default `docker run axllent/mailpit:latest` deploy. An unauthenticated remote attacker can post a multi-million-element `IDs` slice and drive RSS from ~25 MiB baseline to ~450 MiB per 16 MB request body. Repeating across multiple connections accumulates the same per-request amplification per process. Version 1.30.1 contains a patch.
INFO
Published Date :
July 20, 2026, 4:17 p.m.
Last Modified :
Oct. 24, 2026, 8:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update Mailpit to version 1.30.1 or later.
- Apply security patches for all Mailpit deployments.
- Review API endpoints for size limits.
- Restrict unauthenticated API access.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-48824.
| URL | Resource |
|---|---|
| https://github.com/axllent/mailpit/releases/tag/v1.30.1 | Release Notes |
| https://github.com/axllent/mailpit/security/advisories/GHSA-28pq-6qxg-wg5r | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-48824 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-48824
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-48824 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-48824 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 24, 2026
Action Type Old Value New Value Added Translation Title: mailpit de axllent, Description: Mailpit es una herramienta de prueba de correo electrónico y una API para desarrolladores. Antes de la versión 1.30.1, la corrección para GHSA-fpxj-m5q8-fphw (CVE-2026-45710, ’Mailpit: Establecer un límite predeterminado de 50 MB p/m para prevenir DoS a través de tamaños de cuerpo ilimitados de SMTP DATA y /api/v1/send’) envolvió solo “POST /api/v1/send” con “http.MaxBytesReader”. Los otros cuatro endpoints de la API de Mailpit con cuerpo JSON “PUT /api/v1/messages” (SetReadStatus), “DELETE /api/v1/messages” (DeleteMessages), “PUT /api/v1/tags” (SetMessageTags) y “POST /api/v1/message/{id}/release” (ReleaseMessage) todavía llaman a “json.NewDecoder(r.Body)” directamente sin límite de tamaño de cuerpo y permanecen accesibles sin autenticación en el despliegue predeterminado de “docker run axllent/mailpit:latest”. Un atacante remoto no autenticado puede publicar un slice “IDs” de varios millones de elementos y llevar el RSS de una línea base de ~25 MiB a ~450 MiB por cuerpo de solicitud de 16 MB. La repetición a través de múltiples conexiones acumula la misma amplificación por solicitud por proceso. La versión 1.30.1 contiene un parche. -
Initial Analysis by [email protected]
Jul. 28, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:axllent:mailpit:*:*:*:*:*:*:*:* versions up to (excluding) 1.30.1 Added Reference Type GitHub, Inc.: https://github.com/axllent/mailpit/releases/tag/v1.30.1 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/axllent/mailpit/security/advisories/GHSA-28pq-6qxg-wg5r Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 20, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-48824', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-20T19:01:37.901255Z'} -
New CVE Received by [email protected]
Jul. 20, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'axllent', 'product': 'mailpit', 'versions': [{'status': 'affected', 'version': '< 1.30.1'}]}] Added Description Mailpit is an email testing tool and API for developers. Prior to version 1.30.1, the fix for GHSA-fpxj-m5q8-fphw (CVE-2026-45710, "Mailpit: Set a default 50MB p/m limit to prevent DoS via unlimited SMTP DATA and /api/v1/send body sizes") wrapped only `POST /api/v1/send` with `http.MaxBytesReader`. The four other Mailpit JSON-body API endpoints `PUT /api/v1/messages` (SetReadStatus), `DELETE /api/v1/messages` (DeleteMessages), `PUT /api/v1/tags` (SetMessageTags), and `POST /api/v1/message/{id}/release` (ReleaseMessage) still call `json.NewDecoder(r.Body)` directly with no body-size cap and remain reachable unauthenticated in the default `docker run axllent/mailpit:latest` deploy. An unauthenticated remote attacker can post a multi-million-element `IDs` slice and drive RSS from ~25 MiB baseline to ~450 MiB per 16 MB request body. Repeating across multiple connections accumulates the same per-request amplification per process. Version 1.30.1 contains a patch. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Added CWE CWE-770 Added Reference https://github.com/axllent/mailpit/releases/tag/v1.30.1 Added Reference https://github.com/axllent/mailpit/security/advisories/GHSA-28pq-6qxg-wg5r