CVE-2026-61548
Rsyslog is a rocket-fast system for log processing. From 7.5.4 until 8.2606.0, the optional mmpstrucdata plugin's parseSD_PARAM function in plugins/mmpstrucdata/mmpstrucdata.c stores RFC5424 parameter values in a fixed pVal[32 * 1024] stack buffer and calls parsePARAM_VALUE without supplying the destination size. A remote unauthenticated attacker whose crafted RFC5424 message reaches an action using mmpstrucdata can provide a structured-data parameter larger than that buffer when MaxMessageSize permits it, causing an attacker-controlled stack overwrite.
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Deployments that do not install and use the plugin, or whose effective message-size limit remains below the required threshold, are not affected by this issue. The demonstrated impact is a crash and interruption of log collection; code execution is not demonstrated. This issue is fixed in version 8.2606.0.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 8.1
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.94%
- Percentil entre todas las CVEs puntuadas: 60
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1190Exploit Public-Facing Applicationinitial access85 % - Impacto principal
T1499.004Application or System Exploitationimpact80 % - Impacto secundario
T1059Command and Scripting Interpreterexecution35 %
Vulnerabilidad de desbordamiento de buffer en aplicación de red (rsyslog) accesible remotamente sin autenticación. Impacto demostrado: DoS por crash; ejecución no demostrada pero posible por escritura controlada de stack.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-121
Referencias
- https://github.com/rsyslog/rsyslog/commit/bcda60a3692efdf0c8e44102528f5a0ebe0dec6d
- https://github.com/rsyslog/rsyslog/pull/6991
- https://github.com/rsyslog/rsyslog/releases/tag/v8.2606.0
- https://github.com/rsyslog/rsyslog/security/advisories/GHSA-8qmr-c66f-g368
- http://www.openwall.com/lists/oss-security/2026/07/20/1
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-61548",
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"role": "CISA Coordinator",
"options": [
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{
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},
{
"technicalImpact": "total"
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"version": "2.0.3",
"timestamp": "2026-09-18T19:24:39.206415Z"
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"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "HIGH",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
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"published": "2026-09-18T17:16:58.190",
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"value": "Rsyslog is a rocket-fast system for log processing. From 7.5.4 until 8.2606.0, the optional mmpstrucdata plugin's parseSD_PARAM function in plugins/mmpstrucdata/mmpstrucdata.c stores RFC5424 parameter values in a fixed pVal[32 * 1024] stack buffer and calls parsePARAM_VALUE without supplying the destination size. A remote unauthenticated attacker whose crafted RFC5424 message reaches an action using mmpstrucdata can provide a structured-data parameter larger than that buffer when MaxMessageSize permits it, causing an attacker-controlled stack overwrite. Deployments that do not install and use the plugin, or whose effective message-size limit remains below the required threshold, are not affected by this issue. The demonstrated impact is a crash and interruption of log collection; code execution is not demonstrated. This issue is fixed in version 8.2606.0."
}
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"lastModified": "2026-09-24T21:22:19.873",
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