SonicWall has patched a SonicOS vulnerability that can be used to bypass SAML authentication, warning customers that it may have been exploited in attacks.
Tracked as CVE-2026-19868, the flaw affects the SSL VPN component of SonicOS, the operating system that runs on SonicWall firewalls. It’s one of seven vulnerabilities described in an advisory published on November 6.
“An authentication enforcement vulnerability in SonicOS SSLVPN service may allow a user with valid credentials for an alternate authentication method to bypass SAML authentication controls. Successful exploitation may also bypass SAML-enforced multi-factor authentication (MFA),” reads SonicWall’s description of CVE-2026-19868.
According to the vendor, an SSL VPN is exposed only if SAML-based login is enabled. CVE-2026-19868 has a CVSS score of 7.1, which puts it in the high-severity range. The flaw was reported by Ryan Harris of The Electronic Office.
SonicWall said its product security team “has investigated a report indicating potential exploitation of this vulnerability.”
CISA added CVE-2026-19868 to its Known Exploited Vulnerabilities (KEV) catalog on the same day. Under Binding Operational Directive 26-04, federal agencies must address it by November 20.
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Neither the vendor nor CISA has shared any details about the suspected attacks. It’s also unclear whether the flaw was exploited as a zero-day, before a patch became available.
Impacted devices include Gen7 TZ, NSa, NSsp and NSv firewalls with SonicOS 7.3.3-7015 or older. Gen8 TZ, NSa and NSv firewalls with SonicOS 8.2.2-8015 or older are also affected.
SonicOS versions 7.3.4-7013 and 8.2.3-8015 resolve the issue, and there are no workarounds. “Customers are strongly urged to upgrade to the latest release as soon as possible to mitigate the associated risks,” SonicWall said.
SonicWall’s advisory doesn’t mark any of the other six flaws as exploited. Two of them, each with a CVSS score of 8.8, affect the SonicOS management interface. One is a permissive cross-domain policy issue and the other is a session validation bug.
Under certain circumstances, a remote attacker could abuse either one without logging in to take unauthorized actions.
Three of the remaining flaws are pre-authentication buffer overflows in the SSL VPN service and the TACACS+ authentication client. Attackers could use them to launch DoS attacks at the application level.
The last one is a weak password hashing issue in virtual appliances. An attacker who already has high-privileged local access could exploit it to obtain a platform credential, which gives access to some of the platform’s settings.
Threat actors often exploit SonicWall product vulnerabilities. CISA’s KEV catalog currently includes 20 security holes, but the agency has yet to add CVE-2026-102255, which hackers started targeting last month, just days after its disclosure.
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https://www.securityweek.com/sonicwall-patches-exploited-sonicos-bug-that-weakens-vpn-logins/
