Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 6.49% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2021
CVE-2020-26139High confidence
This might be abused in projected Wi-Fi networks to launch denial-of-service attacks against connected clients and makes it easier to exploit other vulnerabilities in connected clients
Unknown · Unknown
Official source articles: Siemens SSA-019200 ↗ · Cisco CISCO-SA-WIFI-FAF-22EPCEWU ↗. Check the applicable product and release in the original source.
5.3MediumCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 114 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Unknown Unknown and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 114 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Siemens ProductCERT: 49 affected or under-investigation product states without a fixed product state in the same current advisory
- Siemens ProductCERT: 64 affected or under-investigation product states without a fixed product state in the same current advisory
- Canonical Ubuntu Security: 1 affected package state with no published fix
Distribution package intelligence
5 package statesRelease-specific package status
Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Package result overrides the generic status
BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 1 affected package state shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 5.10.46-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian bookwormbookworm · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 5.10.46-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian forkyforky · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 5.10.46-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian sidsid · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 5.10.46-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-raspi-realtime | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 6 Oct 2026 |
Direct vendor intelligence
2 currentAuthoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
SSA-019200 · CSAF 2.0 · revision 1 · interimSiemens ProductCERTSSA-019200: Multiple Vulnerabilities in SCALANCE W-700 IEEE 802.11n Devices Before V6.6.0
The vendor explicitly identifies these products as affected by this CVE.
- SCALANCE W721-1 RJ45 (6GK5721-1FC00-0AA0)
- SCALANCE W721-1 RJ45 (6GK5721-1FC00-0AB0)
- SCALANCE W722-1 RJ45 (6GK5722-1FC00-0AA0)
- SCALANCE W722-1 RJ45 (6GK5722-1FC00-0AB0)
- SCALANCE W722-1 RJ45 (6GK5722-1FC00-0AC0)
- SCALANCE W734-1 RJ45 (6GK5734-1FX00-0AA0)
- SCALANCE W734-1 RJ45 (6GK5734-1FX00-0AA6)
- SCALANCE W734-1 RJ45 (6GK5734-1FX00-0AB0)
- SCALANCE W734-1 RJ45 (USA) (6GK5734-1FX00-0AB6)
- SCALANCE W738-1 M12 (6GK5738-1GY00-0AA0)
- SCALANCE W738-1 M12 (6GK5738-1GY00-0AB0)
- SCALANCE W748-1 M12 (6GK5748-1GD00-0AA0)
- Summary
- An issue was discovered in the kernel in NetBSD 7.1. An Access Point (AP) forwards EAPOL frames to other clients even though the sender has not yet successfully authenticated to the AP. This might be abused in projected Wi-Fi networks to launch denial-of-service attacks against connected clients and makes it easier to exploit other vulnerabilities in connected clients.
- Remediation
- Update to V6.6.0 or later version
SSA-913875 · CSAF 2.0 · revision 6 · interimSiemens ProductCERTSSA-913875: Frame Aggregation and Fragmentation Vulnerabilities in 802.11
The vendor explicitly identifies these products as affected by this CVE.
- SCALANCE W1748-1 M12 (6GK5748-1GY01-0AA0)
- SCALANCE W1748-1 M12 (6GK5748-1GY01-0TA0)
- SCALANCE W1788-1 M12 (6GK5788-1GY01-0AA0)
- SCALANCE W1788-2 EEC M12 (6GK5788-2GY01-0TA0)
- SCALANCE W1788-2 M12 (6GK5788-2GY01-0AA0)
- SCALANCE W1788-2IA M12 (6GK5788-2HY01-0AA0)
- SCALANCE W721-1 RJ45 (6GK5721-1FC00-0AA0)
- SCALANCE W721-1 RJ45 (6GK5721-1FC00-0AB0)
- SCALANCE W722-1 RJ45 (6GK5722-1FC00-0AA0)
- SCALANCE W722-1 RJ45 (6GK5722-1FC00-0AB0)
- SCALANCE W722-1 RJ45 (6GK5722-1FC00-0AC0)
- SCALANCE W734-1 RJ45 (6GK5734-1FX00-0AA0)
- Summary
- An issue was discovered in the kernel in NetBSD 7.1. An Access Point (AP) forwards EAPOL frames to other clients even though the sender has not yet successfully authenticated to the AP. This might be abused in projected Wi-Fi networks to launch denial-of-service attacks against connected clients and makes it easier to exploit other vulnerabilities in connected clients.
- Remediation
- Update to V1.2.0 or later version
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 114 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
An issue was discovered in the kernel in NetBSD 7.1. An Access Point (AP) forwards EAPOL frames to other clients even though the sender has not yet successfully authenticated to the AP. This might be abused in projected Wi-Fi networks to launch denial-of-service attacks against connected clients and makes it easier to exploit other vulnerabilities in connected clients.
What
An issue was discovered in the kernel in NetBSD 7.1. An Access Point (AP) forwards EAPOL frames to other clients even though the sender has not yet successfully authenticated to the AP. This might be abused in projected Wi-Fi networks to launch denial-of-service attacks against connected clients and makes it easier to exploit other vulnerabilities in connected clients.
Why
The affected component does not establish the requesting party's identity reliably before granting access.
How
An attacker operating through the affected interface may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
An issue was discovered in the kernel in NetBSD 7.1. An Access Point (AP) forwards EAPOL frames to other clients even though the sender has not yet successfully authenticated to the AP. This might be abused in projected Wi-Fi networks to launch denial-of-service attacks against connected clients and makes it easier to exploit other vulnerabilities in connected clients.
Why
The affected component does not establish the requesting party's identity reliably before granting access.
How
An attacker operating through the affected interface may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- the affected interface → Improper Authentication → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Unspecified
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- High: exploitation depends on specific conditions
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-287 ↗
CWE-287: Improper Authentication. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVAdjacentAttack vector: The attacker must be on an adjacent or logically close network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix availability varies by product
- Affected
- SCALANCE W721-1 RJ45 (6GK5721-1FC00-0AA0)
- SCALANCE W721-1 RJ45 (6GK5721-1FC00-0AB0)
- SCALANCE W722-1 RJ45 (6GK5722-1FC00-0AA0)
- SCALANCE W722-1 RJ45 (6GK5722-1FC00-0AB0)
- SCALANCE W722-1 RJ45 (6GK5722-1FC00-0AC0)
- SCALANCE W734-1 RJ45 (6GK5734-1FX00-0AA0)
- SCALANCE W734-1 RJ45 (6GK5734-1FX00-0AA6)
- SCALANCE W734-1 RJ45 (6GK5734-1FX00-0AB0)
- SCALANCE W734-1 RJ45 (USA) (6GK5734-1FX00-0AB6)
- SCALANCE W738-1 M12 (6GK5738-1GY00-0AA0)
- SCALANCE W738-1 M12 (6GK5738-1GY00-0AB0)
- SCALANCE W748-1 M12 (6GK5748-1GD00-0AA0)
- SCALANCE W748-1 M12 (6GK5748-1GD00-0AB0)
- SCALANCE W748-1 RJ45 (6GK5748-1FC00-0AA0)
- SCALANCE W748-1 RJ45 (6GK5748-1FC00-0AB0)
- SCALANCE W761-1 RJ45 (6GK5761-1FC00-0AA0)
- SCALANCE W761-1 RJ45 (6GK5761-1FC00-0AB0)
- SCALANCE W774-1 M12 EEC (6GK5774-1FY00-0TA0)
- SCALANCE W774-1 M12 EEC (6GK5774-1FY00-0TB0)
- SCALANCE W774-1 RJ45 (6GK5774-1FX00-0AA0)
- SCALANCE W774-1 RJ45 (6GK5774-1FX00-0AA6)
- SCALANCE W774-1 RJ45 (6GK5774-1FX00-0AB0)
- SCALANCE W774-1 RJ45 (6GK5774-1FX00-0AC0)
- SCALANCE W774-1 RJ45 (USA) (6GK5774-1FX00-0AB6)
- SCALANCE W778-1 M12 (6GK5778-1GY00-0AA0)
- SCALANCE W778-1 M12 (6GK5778-1GY00-0AB0)
- SCALANCE W778-1 M12 EEC (6GK5778-1GY00-0TA0)
- SCALANCE W778-1 M12 EEC (USA) (6GK5778-1GY00-0TB0)
- SCALANCE W786-1 RJ45 (6GK5786-1FC00-0AA0)
- SCALANCE W786-1 RJ45 (6GK5786-1FC00-0AB0)
- and 19 more
- Action
- Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 11 May 2021 · Last source change 14 Apr 2026, 08:49 UTC · CWE-287 · Improper Authentication
CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2020-18766
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceNIST NVD
NVD statusNVD modified after enrichment
Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.
Material change intelligence
View recent updates ↗What changed after publication
- Affected versionsThe structured affected or fixed version information changed.Siemens ProductCERT ↗
- Before
- n/a · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- After
- n/a · Fixed: Update to V6.6.0 or later version
CVE published
Fixed release or patch reference recorded
Fixed release recorded from official guidance
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.