Evidence used
- CISA confirms exploitation in the wild.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 1.72% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-65400High confidence
Apple macOS Improper Authentication Vulnerability
Apple · macOS
9.8CriticalCVSS 3.1
Mitigate now
Mitigation availableCISA confirms exploitation in the wild and lists 2026-08-21 as the remediation due date.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityCritical→Operational priority:Critical, unchanged from published severity.unchanged
Compensating controls
- Apply the linked authoritative mitigation while planning the permanent fix.
- Restrict the affected network interface to trusted sources where business-safe.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs Apple macOS and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
CISA confirms exploitation in the wild and lists 2026-08-21 as the remediation due date.
Mitigation available01
What, why and how
Apple macOS contains an improper authentication vulnerability that could allow an attacker on the network to authenticate to Screen Sharing without valid credentials.
What
Apple macOS contains an improper authentication vulnerability that could allow an attacker on the network to authenticate to Screen Sharing without valid credentials.
Why
The affected component does not establish the requesting party's identity reliably before granting access.
How
An attacker operating through a network path 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
Apple macOS contains an improper authentication vulnerability that could allow an attacker on the network to authenticate to Screen Sharing without valid credentials.
Why
The affected component does not establish the requesting party's identity reliably before granting access.
How
An attacker operating through a network path 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 Confirmed in the wild
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2026-08-18.
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
- a network path → Improper Authentication → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- 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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.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.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
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. - Mitigation available
- Action
- In linea con le dichiarazioni del vendor, si raccomanda di applicare le patch seguendo le indicazioni riportate nei bollettini di sicurezza, disponibili nella sezione Riferimenti.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
Official vendor articles5 stored documents
Linked articles are downloaded and versioned as source evidence. A CVE mention or approved update relationship does not, by itself, verify a fix for every product branch.
- About the security content of macOS Sonoma 14.8.9 - Apple Support →Original publisher ↗Searchable text snapshot · Captured 27 Sep 2026Apple Store Mac iPad iPhone Watch Vision AirPods TV & Home Entertainment Accessories Support 0 + "},{"name":"compact","assetInline":" "}],"analyticsAttributes":[{"name":"data-analytics-title","value":"apple home"}]},{"id":"ad4a2a26eb4836393385e9f6c61b526b4a3cb31409c5ed8730ce7a704dd7132f","name":"store","te
- About the security content of macOS Tahoe 26.6.1 - Apple Support →Original publisher ↗Searchable text snapshot · Captured 26 Sep 2026Apple Store Mac iPad iPhone Watch Vision AirPods TV & Home Entertainment Accessories Support 0 + "},{"name":"compact","assetInline":" "}],"analyticsAttributes":[{"name":"data-analytics-title","value":"apple home"}]},{"id":"ad4a2a26eb4836393385e9f6c61b526b4a3cb31409c5ed8730ce7a704dd7132f","name":"store","te
- About the security content of macOS Sequoia 15.7.9 - Apple Support →Original publisher ↗Searchable text snapshot · Captured 26 Sep 2026Apple Store Mac iPad iPhone Watch Vision AirPods TV & Home Entertainment Accessories Support 0 + "},{"name":"compact","assetInline":" "}],"analyticsAttributes":[{"name":"data-analytics-title","value":"apple home"}]},{"id":"ad4a2a26eb4836393385e9f6c61b526b4a3cb31409c5ed8730ce7a704dd7132f","name":"store","te
- About the security content of macOS Golden Gate 27 - Apple Support →Original publisher ↗Searchable text snapshot · Captured 26 Sep 2026Apple Store Mac iPad iPhone Watch Vision AirPods TV & Home Entertainment Accessories Support 0 + "},{"name":"compact","assetInline":" "}],"analyticsAttributes":[{"name":"data-analytics-title","value":"apple home"}]},{"id":"ad4a2a26eb4836393385e9f6c61b526b4a3cb31409c5ed8730ce7a704dd7132f","name":"store","te
- About the security content of macOS Tahoe 26.7 - Apple Support →Original publisher ↗Searchable text snapshot · Captured 26 Sep 2026Apple Store Mac iPad iPhone Watch Vision AirPods TV & Home Entertainment Accessories Support 0 + "},{"name":"compact","assetInline":" "}],"analyticsAttributes":[{"name":"data-analytics-title","value":"apple home"}]},{"id":"ad4a2a26eb4836393385e9f6c61b526b4a3cb31409c5ed8730ce7a704dd7132f","name":"store","te
04
Evidence and provenance
Published 6 Aug 2026 · Last source change 14 Sept 2026, 20:48 UTC · CWE-287 · Improper Authentication
CVE recordCVE.org · 5.2
CVSS sourceCISA ADP
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-2026-54216
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- BlackTree coverageBlackTree article coverage changed from 1 BlackTree article to 2 BlackTree articles.BlackTree editorial ↗
- Before
- 1 BlackTree article
- After
- 2 BlackTree articles
- Remediation statusRemediation status changed from Awaiting fix to Mitigation available.CSIRT Italia ↗
- Before
- Awaiting fix
- After
- Mitigation available
- Vendor guidanceAuthoritative vendor guidance changed: removed remediation: acn.gov.it/aggiornamenti-di-sicurezza-apple-19.product-security@apple.com ↗
- Before
- remediation: acn.gov.it/aggiornamenti-di-sicurezza-apple-19 · vendor advisory: support.apple.com/148170 · vendor advisory: support.apple.com/148171 · 3 more references
- After
- vendor advisory: support.apple.com/148170 · vendor advisory: support.apple.com/148171 · vendor advisory: support.apple.com/148172 · 2 more references
- Remediation statusRemediation status changed from Mitigation available to Awaiting fix.product-security@apple.com ↗
- Before
- Mitigation available
- After
- Awaiting fix
- Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: support.apple.com/149035; added vendor advisory: support.apple.com/149042.product-security@apple.com ↗
- Before
- vendor advisory: support.apple.com/148170 · vendor advisory: support.apple.com/148171 · vendor advisory: support.apple.com/148172
- After
- vendor advisory: support.apple.com/148170 · vendor advisory: support.apple.com/148171 · vendor advisory: support.apple.com/148172 · 2 more references
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- macOS: < 14.8.9, < 15.7.9, < 26.6.1 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- macOS: < 14.8.9, < 15.7.9, < 26.6.1, < 26.7, < 27 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- Affected versionsThe structured affected or fixed version information changed.CNA ↗
- Before
- < 14.8.9; < 15.7.9; < 26.6.1 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- macOS: < 14.8.9, < 15.7.9, < 26.6.1 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- CISA KEV stateCISA KEV now confirms exploitation in the wild.CISA KEV ↗
- Before
- not listed in CISA KEV
- After
- listed in CISA KEV since 2026-08-18
- BlackTree coverageBlackTree article coverage changed from no BlackTree article to 1 BlackTree article.BlackTree editorial ↗
- Before
- no BlackTree article
- After
- 1 BlackTree article
- SeveritySeverity changed from High to Critical.CISA ADP ↗
- Before
- High
- After
- Critical
- CVSS scoreCVSS changed from 7.1 (CVSS 3.1) to 9.8 (CVSS 3.1).CISA ADP ↗
- Before
- 7.1 (CVSS 3.1 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N)
- After
- 9.8 (CVSS 3.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVE published
Added to CISA KEV
Remediation guidance recorded
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.