Cisco Secure Firewall ASA/FTD SAML SSO DoS
CVE-2026-20101 is a denial-of-service vulnerability in the SAML 2.0 single sign-on (SSO) feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software. The issue is caused by insufficient error checking when processing SAML messages. A remote, unauthenticated attacker can send crafted SAML messages to the exposed SAML service and trigger an unexpected device reload. The vulnerable condition is in SAML message handling within the Remote Access SSL VPN authentication workflow, and successful exploitation results in the affected firewall reloading unexpectedly.
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Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
15 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Unauthenticated remote denial-of-service vulnerability in Cisco Secure Firewall ASA and Secure FTD SAML 2.0 SSO processing, where crafted SAML messages can trigger an unexpected reload.
Denial of service vulnerability affecting Cisco ASA and Cisco Secure Firewall Threat Defense (FTD) Remote Access SSL VPN.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.