Security readout for executives and security teams
Plain-English summary
This Cisco MME flaw can interrupt mobile network connectivity by causing an MME to stop sending SCTP messages to a connected eNodeB. It affects Cisco ASR 5000 Series Software in MME deployments. Exploitation requires a man-in-the-middle position between the eNodeB and MME, which reduces likelihood but the availability impact is high.
Executive priority
Treat as a targeted telecom availability risk, not a broad internet-exposed emergency. Prioritize review for mobile core environments using Cisco ASR 5000 MME, especially where transport-path trust is weak or service availability requirements are strict.
Technical view
CVE-2019-16026 is an insufficient input validation issue in Cisco MME SCTP handling. An unauthenticated remote attacker with man-in-the-middle positioning between eNodeB and MME could send crafted SCTP traffic to the MME, causing it to stop SCTP communication with the eNodeB and trigger denial of service.
Likely exposure
Exposure is likely limited to operators running Cisco ASR 5000 Series Software as an MME. Risk depends on whether attackers can access or intercept the SCTP path between eNodeB and MME.
Exploitation context
The CVE record does not indicate KEV listing or active exploitation. The documented attack path requires network positioning between the eNodeB and MME plus crafted SCTP traffic, reflected by high attack complexity in CVSS.
Researcher notes
The public bundle identifies Cisco ASR 5000 Series Software with unspecified versions. It provides the attack condition, impact, CVSS 6.8, CWE-20, and vendor advisory reference, but detailed fixed-release data is not included in the bundle.
Mitigation direction
- Review Cisco advisory cisco-sa-20200108-mme-dos for affected releases and fixed software.
- Inventory Cisco ASR 5000 MME deployments and map connected eNodeB SCTP paths.
- Apply Cisco-recommended software updates or mitigations where deployed versions match the advisory.
- Restrict MME-eNodeB SCTP connectivity to trusted transport paths where operationally feasible.
- Monitor for unexpected SCTP session disruption between MME and eNodeB systems.
Validation and detection
- Confirm whether Cisco ASR 5000 Series Software is used for MME functions.
- Compare installed ASR 5000 software versions with Cisco advisory affected-release details.
- Review topology for systems able to intercept or inject traffic on MME-eNodeB SCTP paths.
- Check operational logs for abnormal SCTP communication loss between MME and eNodeB.
- Verify remediation status against Cisco advisory guidance after any maintenance window.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-20: 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.
Open ATT&CK lookupCVE-2019-16026 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H
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.
CVSS vector scores
1 official scoreWe 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.
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H2.24Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
6.8MediumVector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20200108 Cisco Mobility Management Entity Denial of Service VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.