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CVE Record

CVE-2026-20026: Multiple Cisco Products Snort 3 DCERPC Vulnerabilities

Multiple Cisco products are affected by a vulnerability in the processing of DCE/RPC requests that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to leak sensitive information or to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in buffer handling logic when processing DCE/RPC requests, which can result in a buffer use-after-free read. An attacker could exploit this vulnerability by sending a large number of DCE/RPC requests through an established connection that is inspected by Snort 3. A successful exploit could allow the attacker to unexpectedly restart the Snort 3 Detection Engine, which could cause a denial of service (DoS).

MediumCVSS 5.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This flaw can let an unauthenticated remote attacker disrupt Cisco Snort 3 inspection by sending many DCE/RPC requests over an inspected connection. Business impact is mainly reduced security monitoring or IPS inspection during engine restarts, not full device takeover based on the provided sources.

Executive priority

Treat this as a moderate operational security risk. Prioritize internet-facing or high-traffic inspection points and environments relying on Cisco Snort 3 for segmentation, malware detection, or compliance monitoring.

Technical view

CVE-2026-20026 is a Snort 3 DCE/RPC processing issue in Cisco Secure Firewall Threat Defense and Cisco UTD SNORT IPS Engine Software. Cisco describes buffer handling logic causing a use-after-free read when processing DCE/RPC requests, potentially restarting the Snort 3 Detection Engine and interrupting packet inspection.

Likely exposure

Exposure is most likely where affected Cisco FTD or UTD SNORT IPS Engine versions inspect DCE/RPC traffic with Snort 3. The attacker does not need credentials, but traffic must pass through an established connection inspected by Snort 3.

Exploitation context

The CVE is not listed as CISA KEV in the provided data, and no source here states active exploitation. The described attack is network-based, low-complexity, and targets availability of inspection rather than device control.

Researcher notes

The source data indicates CWE-415, though the description specifically says use-after-free read. CVSS is 5.8 with availability impact only. The source bundle does not provide patch version details, so remediation should be tied directly to Cisco’s advisory.

Mitigation direction

  • Identify Cisco FTD and UTD SNORT IPS Engine deployments using affected versions.
  • Review the Cisco advisory for fixed releases, workarounds, and deployment-specific guidance.
  • Plan updates for affected inspection points according to Cisco guidance and operational risk.
  • Monitor Snort 3 engine restarts and DCE/RPC inspection anomalies.

Validation and detection

  • Compare deployed Cisco FTD and UTD SNORT IPS Engine versions against the affected-version lists.
  • Confirm whether Snort 3 is enabled and inspecting DCE/RPC traffic paths.
  • Review device and management logs for unexpected Snort 3 Detection Engine restarts.
  • Track Cisco advisory updates for remediation status and corrected release information.
Prepared
Confidence
high
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-415: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2026-20026 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
5.8CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L3.91.4Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

5.8Medium
CVSS 3.1 vector shape for CVE-2026-20026Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
CiscoCisco Secure Firewall Threat Defense (FTD) Software7.0.0, 7.0.0.1, 7.0.1, 7.1.0, 7.0.1.1, 7.1.0.1, 7.0.2, 7.2.0, 7.0.2.1, 7.0.3, 7.1.0.2, 7.2.0.1, 7.0.4, 7.2.1, 7.0.5, 7.3.0, 7.2.2, 7.2.3, 7.3.1, 7.1.0.3, 7.2.4, 7.0.6, 7.2.5, 7.2.4.1, 7.3.1.1, 7.4.0, 7.0.6.1, 7.2.5.1, 7.4.1, 7.2.6, 7.0.6.2, 7.4.1.1, 7.2.7, 7.2.5.2, 7.3.1.2, 7.2.8, 7.6.0, 7.4.2, 7.2.8.1, 7.0.6.3, 7.4.2.1, 7.2.9, 7.0.7, 7.7.0, 7.4.2.2, 7.2.10, 7.6.1, 7.4.2.3, 7.0.8, 7.6.2, 7.7.10, 7.0.8.1, 7.6.2.1, 7.7.10.1, 7.4.2.4, 7.2.10.2, 7.4.3unknown
CiscoCisco UTD SNORT IPS Engine Software3.17.1S, 16.12.3, Fuji-16.9.5, 16.12.4, 17.3.1a, 16.6.6, 16.12.2, Fuji-16.9.6, 3.17.0S, Fuji-16.9.3, Denali-16.3.7, Fuji-16.9.2, Fuji-16.9.4, Everest-16.6.4, Everest-16.6.3, 16.6.5, Denali-16.3.5, 17.2.1r, 17.1.1, Everest-16.6.2, 16.6.7a, Denali-16.3.4, 16.6.1, Denali-16.3.9, Denali-16.3.3, 16.12.1a, 17.3.2, 17.4.1a, 16.12.5, 17.5.1, Fuji-16.9.7, 16.6.9, 17.3.3, 17.5.1a, 17.3.4, 17.3.4a, 17.4.2, 17.4.1b, 17.6.1a, 16.6.10, 17.7.1a, 16.12.6, Fuji-16.9.8, 17.6.2, 17.8.1a, 16.12.7, 17.3.5, 17.6.3, 17.6.3a, 17.7.2, 17.9.1a, 17.6.4, 17.10.1a, 17.3.6, 16.12.8, 17.3.7, 17.9.2a, 17.6.5, 17.11.1a, 17.9.3a, 17.12.1a, 17.9.4, 17.6.6, 17.3.8, 17.3.8a, 17.6.6a, 17.9.4a, 17.12.2, 17.13.1a, 17.9.5a, 17.12.3, 17.6.7, 17.14.1a, 17.12.4, 17.12.3a, 17.15.1a, 17.6.8, 17.9.6, 17.6.8a, 17.16.1a, 17.9.5e, 17.12.4a, 17.15.2c, 17.9.5f, 17.12.4b, 17.15.2a, 17.12.5, 17.17.1, 17.12.5a, 17.9.7a, 17.15.3a, 17.15.3, 17.12.5b, 17.12.5c, 17.15.4, 17.9.7b, 17.18.1, 17.18.1a, 17.12.6, 17.9.8, 17.15.4c, 17.12.5d, 17.18.2unknown
Weakness

CWE details

CWE-415

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-415 · source CWE mapping

Double Free

Double Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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