CVSS 4.0
2.1 lowCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:PCVE-2026-122020
Low (2.1) in nst labs tech nstbrowser. EPSS 0.3% estimated probability of exploitation activity in the next 30 days.
On this page
A security flaw has been discovered in NST Labs Tech Nstbrowser up to 1.2.1. The affected element is the function stopAllBrowsers of the file /api/agent/browser/stopAll of the component Local Agent Management Service. Performing a manipulation results in denial of service. Remote exploitation of the attack is possible. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.
Severity
CVSS 3.1
4.3 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L- EPSS
- 0.3% estimated probability of exploitation activity in the next 30 days; 25th percentile. Scored 2026-11-10. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: PoC · Automatable: no · Technical impact: partial, assessed 2026-11-09. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-404 Improper Resource Shutdown or Release
- Published
- Modified
- NVD analysis
- Deferred: the NVD does not plan to analyze it
- Record from
- the NVD, synced
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Explain CVE-2026-122020 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-122020?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-122020?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-122020 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Affected
- nst labs tech:nstbrowser
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| NST Labs Tech Nstbrowser | 1.2.0 |
| NST Labs Tech Nstbrowser | 1.2.1 |
Red Hat
Red Hat rates this Moderate.
This vulnerability is rated with Moderate severity because exploitation requires user interaction and is limited to causing a denial of service on the browser service without impacting data confidentiality or integrity. Additionally, Nstbrowser is not packaged, shipped, or supported in Red Hat products. As a result, this issue does not affect any supported Red Hat software.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Contains Red Hat Security Data © Red Hat, Inc., licensed under CC BY 4.0. Source: https://access.redhat.com/security/data. Modified: reformatted. Red Hat's page for CVE-2026-122020.
Attack patterns (CAPEC)
- CAPEC-125 Flooding Likelihood: High · Severity: Medium
- CAPEC-130 Excessive Allocation Likelihood: Medium · Severity: Medium
- CAPEC-131 Resource Leak Exposure Likelihood: Medium · Severity: Medium
- CAPEC-494 TCP Fragmentation
- CAPEC-495 UDP Fragmentation
- CAPEC-496 ICMP Fragmentation
- CAPEC-666 BlueSmacking Likelihood: Medium · Severity: Medium
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.