Cisco Catalyst SD-WAN flaw exploited in wild
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CERT-FR warns an actively exploited Cisco Catalyst SD-WAN vulnerability allows attackers to bypass security policy enforcement.
CERT-FR has issued an advisory regarding CVE-2026-76504, a vulnerability in Cisco Catalyst SD-WAN Software that allows an attacker to bypass the security policy. Cisco has confirmed that this vulnerability is being actively exploited in the wild, making it a priority for affected organizations to patch immediately.
Multiple versions of Catalyst SD-WAN Software are affected, including releases prior to 20.9.10.1, 20.12.8.2, 20.15.6.1, 20.18.4.1, 26.1.2.1, and 26.2.1. The vulnerability relates to web authentication handling (referenced as 'sdwan-webauth' in Cisco's advisory naming), though specific technical details of the exploitation mechanism are not disclosed in this bulletin. Organizations running Catalyst SD-WAN should consult Cisco's security advisory (cisco-sa-sdwan-webauth-xr8beuuU) for patch guidance and apply fixes immediately given confirmed active exploitation.
Defenders operating Cisco SD-WAN infrastructure should treat this as an urgent patching priority, verify current software versions against the affected ranges listed, and monitor for anomalous authentication or policy bypass activity on SD-WAN management interfaces until patches are applied.
Mentioned in this report
Source reporting: https://www.cert.ssi.gouv.fr/avis/CERTFR-2026-AVI-1246
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