Security readout for executives and security teams
Plain-English summary
CVE-2026-21634 is a denial-of-service issue in Ubiquiti UniFi Protect Application 6.1.79 and earlier. An attacker on the same adjacent network could overflow the discovery protocol and cause the application to restart. The main business impact is temporary loss or disruption of video security management, not data theft based on current sources.
Executive priority
Treat as a moderate operational resilience issue. Patch promptly where UniFi Protect supports physical security, regulated monitoring, or high-availability surveillance. The urgency increases if the Protect system is reachable from shared or weakly segmented local networks.
Technical view
The CVE describes a CWE-119 buffer overflow in the UniFi Protect Application discovery protocol. CVSS 3.1 is 6.5 with adjacent-network access, low complexity, no privileges, no user interaction, and high availability impact. Confidentiality and integrity impacts are listed as none. Ubiquiti states updating to version 6.2.72 or later mitigates the issue.
Likely exposure
Exposure is limited to UniFi Protect Application deployments running version 6.1.79 or earlier where an untrusted actor can reach the adjacent-network discovery protocol. Internet-wide exposure is not indicated by the provided sources.
Exploitation context
No active exploitation is stated in the source bundle, and the CVE is not marked as CISA KEV. Exploitation requires adjacent-network access, which reduces broad remote risk but remains relevant for flat office, campus, guest, or compromised internal networks.
Researcher notes
Public details are limited to the vendor advisory and CVE record. The described impact is application restart from discovery protocol overflow. Avoid assuming code execution or data compromise; the published CVSS vector only supports availability impact from adjacent-network attack conditions.
Mitigation direction
- Update UniFi Protect Application to version 6.2.72 or later.
- Prioritize sites where camera systems share networks with untrusted users or devices.
- Review Ubiquiti’s advisory for any environment-specific deployment notes.
Validation and detection
- Inventory UniFi Protect Application versions across all consoles and appliances.
- Confirm affected deployments are version 6.1.79 or earlier.
- Verify upgraded systems report version 6.2.72 or later.
- Check monitoring for unexpected UniFi Protect application restarts.
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-119: 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-2026-21634 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
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/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:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
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 Restriction of Operations within the Bounds of a Memory Buffer
Improper Restriction of Operations within the Bounds of a Memory Buffer represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.