CVE-2026-20291
CVE-2026-20291 is covered by the cisco-sa-hardening-snort3-ybgmhTQe security bulletin. Not in the CISA KEV catalog. Critical advisory severity.
Compare the source-linked records below. Ratings and product/version details belong to each advisory; they are not a single CVE-wide score or proof that every listed product is affected. How VulniPulse collects and checks evidence.
CVE-2026-20291 at a glance
- CISA KEV
- Not listed (catalog checked )
- Highest advisory severity
- Critical
- Vendor advisories
- 2 from Cisco
- VulniPulse record
- Published · Updated
Is CVE-2026-20291 exploited?
No exploitation is reported in the sources VulniPulse tracks: CVE-2026-20291 is not in the CISA KEV catalog (checked ) and no tracked advisory for it reports exploitation. That is not proof the vulnerability cannot be exploited.
How do I fix CVE-2026-20291?
This CVE is tracked through a multi-CVE bulletin, so its fixed releases may differ from the bulletin-wide values below. Check the vendor source.
Vendor advisory comparison
Cisco
2 advisories- Advisory severityCritical9.0
Critical [CVE-2026-20043 +3] Multiple Cisco Products Snort 3 Security Hardening Release: October 2026
cisco-sa-hardening-snort3-ybgmhTQeSource published Source updated
This bulletin covers 4 CVEs. The products, versions, score and guidance below describe the bulletin; check its source for applicability to this specific CVE.
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco owned Open Source Snort 3 Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20043 are related to issues concerning out-of-bounds writes that are grouped under the Common Weakness Enumeration (CWE) Base CWE-787. These vulnerabilities were found during internal testing and are not known to be actively exploited. To assist customers in patching and to streamline the disclosure process, Cisco has grouped these issues by their underlying vulnerability class - Common Weakness Enumeration (CWE) - and assigned a single…
- Affected products in this advisory
- Secure Firewall Threat Defense (FTD) Software
- Cyber Vision
- UTD SNORT IPS Engine Software
- Open Source Snort3
- Source-reported affected versions
- Scope: These vulnerabilities affect the following products, regardless of device configuration:
- Release 3.x (first fixed: 3.12.4.0)
- Earlier than 5.6 — Migrate to a fixed release
- Release 5.6 (first fixed: 5.6.0)
12 more entries in the full advisory.
- Source-reported fixed versions
- 3.12.4.0
- 5.6.0
- 7.0.10
- 7.2.12
10 more entries in the full advisory.
- Mitigation guidance
- Upgrade to the first fixed release for your train per the Fixed Releases table in this advisory.
- Release 3.x: upgrade to 3.12.4.0.
- Earlier than 5.6: migrate to a fixed release.
- Release 5.6: upgrade to 5.6.0.
5 more entries in the full advisory.
- Workarounds
- There are no workarounds that address these vulnerabilities.
- Advisory severityUnrated
Advisory [CVE-2026-20011 +12] Cisco Advance Notification for Publication of October 21, 2026, Security Advisories
cisco-sa-notice-QGwHnJ6kSource published Source updated
This bulletin covers 13 CVEs. The products, versions, score and guidance below describe the bulletin; check its source for applicability to this specific CVE.
On October 21, 2026, the Cisco Product Security Incident Response Team (PSIRT) published the following advisories. To remediate the vulnerabilities that were disclosed on October 21, 2026, Cisco strongly recommends that customers upgrade to the fixed software that is indicated in the advisories. For more information about changes in Cisco PSIRT vulnerability disclosure, see Strengthening the Foundation: A Predictable, Customer-Focused Response to AI-Accelerated Vulnerability Discovery. Snort 3 Cisco Security Advisory CVE ID Security Impact Rating CVSS Base Score Critical 9.0 High 7.8 Medium 5.8 5.3 Cisco Expressway and Unified Communications Products
- Affected products in this advisory
- No product details extracted. Check the source bulletin.
- Source-reported affected versions
- Affected-version details not available in this record.
- Source-reported fixed versions
- No fixed-version detail extracted. This does not mean no fix exists.
- Mitigation guidance
- To remediate the vulnerabilities that were disclosed on October 21, 2026, Cisco strongly recommends that customers upgrade to the fixed software that is indicated in the advisories.
Browse the latest tracked CVEs or the CVEs listed in CISA KEV.
Android app · Google Play
Monitor future Cisco CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 34 official vendor sources and 160+ reviewed platform categories.