Quick answers
- Is CVE-2026-20052 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-20052 being exploited in the wild.
- How severe is CVE-2026-20052?
- Medium severity, with a CVSS score of 5.8, published 4 March 2026.
- Which products and versions are affected?
- Cisco Secure Firewall Threat Defense.
- Is there a fix for CVE-2026-20052?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-20052 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-20052?
- Check whether you run Cisco Secure Firewall Threat Defense. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
This vulnerability is a memory management logic error (CWE-788) in the Snort 3 Detection Engine's SSL packet inspection functionality. An unauthenticated remote attacker can exploit it by sending crafted SSL packets through an established connection. The vulnerability requires Snort 3 to be enabled and an SSL decryption policy to be configured on the device. Successful exploitation causes a denial of service by forcing the Snort 3 Detection Engine to restart, temporarily disabling threat detection. Cisco has released software updates to address this issue; no workarounds are available.
Affected products
- Cisco Secure Firewall Threat Defense
Timeline
- 2026-03-04: disclosed