CVE-2026-20131

criticalpriority · act · 90KEV · exploitedEPSS 0.432 · 99 %ileexploit · PoCDEEUNLRUUS

grimoire priorityP0 · Act now

Exploitable?

Yes · in the wild

CISA KEV · 5 exploits · PoC

Likely / severe?

43.2% (99th) EPSS

CVSS 10 · critical

Is it mine?

215 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

added 2026-03-19remediate by 2026-03-22

required action Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

EPSS · scored 2026-10-20

Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management Deserialization of Untrusted Data Vulnerability

A vulnerability in the web-based management interface of Cisco Secure Firewall Management Center (FMC) Software could allow an unauthenticated, remote attacker to execute arbitrary Java code as root on an affected device. This vulnerability is due to insecure deserialization of a user-supplied Java byte stream. An attacker could exploit this vulnerability by sending a crafted serialized Java object to the web-based management interface of an affected device. A successful exploit could allow the attacker to execute arbitrary code on the device and elevate privileges to root. Note: If the FMC management interface does not have public internet access, the attack surface that is associated with this vulnerability is reduced.

cvss

Technical severity, 0–10. One row per scoring source.

10.0

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.110criticalAV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.110criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:Hsecondary · ENISA EU

v3.110criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:Hsecondary · psirt@cisco.com USexploitability 3.9 · impact 6

v3.110criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:Hsecondary · CVSS-BT (t0sche)

v3.110criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:Hsecondary · NCSC-NL NL

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: active · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-502USCWE-502USCWE-502US

exploits (5)

Public proof-of-concept and weaponised exploit code.

0xBlackash/CVE-2026-20131CVE-2026-20131PoC · poc_in_github
Hassan-Pouladi/Cisco-FMC-honeypotOriginally a Honeypot for CVE-2026-20131PoC · poc_in_github
Jwa7470/CVE-2026-20131-Post-Incident-Written-ReportPost-incident report on CVE-2026-20131 (CVSS 10.0), a Cisco FMC insecure deserialization vulnerability exploited by Interlock ransomware. Details root-cause analysis, lateral movement tactics, and emergency containment strategies.PoC · poc_in_github
p3Nt3st3r-sTAr/CVE-2026-20131-POCp3Nt3st3r-sTAr/CVE-2026-20131-POCPoC · poc_in_github
sak110/CVE-2026-20131sak110/CVE-2026-20131PoC · poc_in_github

affected products (215)

Products and version ranges known to be affected.

Cisco Secure Firewall Management Centerall versionscert_bundDEcpe:/a:cisco:secure_firewall_management_center:-
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.2.7enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 6.4.0.18enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.0.4enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.2.6enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.2.4.1enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 6.4.0.15enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.4.1enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.1.0.2enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.4.3enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.6.0enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.1.0.1enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.7.10.1enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.1.0.3enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.2.10.1enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.4.2.2enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.0.8enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.4.2.1enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.1.0enisa_euvdEU
Cisco Cisco Secure Firewall Management Center (FMC)≤ 7.2.1enisa_euvdEU

showing 20 of 215

advisories (2)

Vendor and ecosystem advisories describing this.

NCSC-2026-0076Kwetsbaarheden verholpen in Cisco Secure Firewall Management CenterNL2026-03-04csaf · ncsc_nlNL
Cisco heeft kwetsbaarheden verholpen in Cisco Secure Firewall Management Center.
WID-SEC-W-2026-0610Cisco Secure Firewall Management Center: Mehrere SchwachstellenDeutsch2026-03-04csaf · cert_bundDE
Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in Cisco Secure Firewall Management Center und Cisco Secure Firewall Threat Defense ausnutzen, um Root-Rechte zu erlangen, beliebigen Code mit Root-Rechten auszuführen, SQL-Injection durchzuführen und vertrauliche Daten offenzulegen sowie Daten zu manipulieren.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund ncsc_nl NVD CVE.org MITRE

published 2026-03-04modified 2026-06-17

references (8)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan