Patch Tuesday - September 2026
The September Patch Tuesday contains an already actively exploited Windows ALPC EoP flaw and, with 999 CVEs, exceeds all previous Microsoft Patch Tuesdays.
Comparing 30 September 2026 with the previous day 29 September 2026.
The September Patch Tuesday contains an already actively exploited Windows ALPC EoP flaw and, with 999 CVEs, exceeds all previous Microsoft Patch Tuesdays.
The report documents a new, previously undisclosed installation and execution technique (RedFlick) used by a Russian state actor, which complicates detection and defense against this campaign.
The report shows that Star Blizzard is scaling its phishing infrastructure with a new RedFlick infection chain and, after hijacking email accounts, now drops a dedicated backdoor (CosmicPulse) , moving beyond pure credential phishing toward persistent compromise of cloud identities.
An unauthenticated attacker can trigger a memory fault in kernel context via a crafted HTTP/1.x request over TLS, potentially leading to code execution with kernel privileges.
The September patch cycle covers 972 CVEs, including two already exploited zero-days and 113 critical vulnerabilities, which drives prioritization of Windows and Office patches.
The report contains no indication of active exploitation or KEV listing; exploitation requires user interaction.
The ZDI advisory describes a use-after-free in Acrobat Reader DC's Annots Report parsing (CVSS 7.8) that is client-side only and requires opening a crafted PDF; no active exploitation is documented.
ZDI-26-667 describes a use-after-free vulnerability in Adobe Acrobat Reader DC rated CVSS 7.8, but contains no indication of active exploitation.
ZDI publishes a use-after-free flaw in Acrobat Reader DC's annotation handling (CVSS 7.8) with no patch reference or evidence of active exploitation provided in the advisory.
The vulnerability requires user interaction via a crafted DCM file or web page, making it suitable for targeted phishing or spear-phishing attacks against design and engineering workstations.
This is a pure vulnerability disclosure with no indication of active exploitation; its added value lies in the file-based attack vector rather than a network perimeter exposure.
The vulnerability is an integer overflow in DCM JPEG image parsing that can be exploited by opening images from untrusted sources.
ZDI documents a type-confusion flaw in Adobe Acrobat Reader DC that leads to code execution with user interaction; active exploitation is not documented.
The ZDI advisory describes a CVSS 7.8 vulnerability that requires user interaction and mentions neither a public exploit nor active exploitation in the wild.
No evidence of active exploitation; the vulnerability has a low CVSS score and requires user interaction.
The attack abuses Entra ID's legitimate device code authentication flow, so no password and no MFA prompt need to be compromised , restricting that flow is the central countermeasure.
The report shows that device code phishing operates as a scalable phishing-as-a-service capability against Microsoft 365, and the takedown of individual domains is only a snapshot in an ongoing arms race.
ZDI published the vulnerability without a CVE ID, complicating tracking in patch management.
The campaign uses Teams chats and calls as a trusted communication channel to impersonate helpdesk staff, thereby bypassing email phishing filters and conventional awareness measures.
AI-powered phishing services such as Eviltokens can harvest Microsoft 365 session tokens at scale and thereby bypass MFA without stealing passwords.
Beyond pure patch information, the report shows that CVE-2026-68820 is already actively exploited and allows local attackers to gain SYSTEM privileges, while macOS and several incidents outside the industry are also affected.
The ZDI advisory describes an unauthenticated information disclosure in Microsoft Entra ID's OAuth Device Code Grant, rated CVSS 5.8 and without an assigned CVE.
The vulnerability requires valid administrator credentials, which limits the exploitation risk to compromised or malicious admin accounts.
The updated BSI advisory provides neither CVE IDs nor attack vectors or exploitation status, so individual kernel vulnerabilities cannot be prioritised.
BSI updates its warning about multiple vulnerabilities in Chrome and Edge without providing specific CVE details or exploit status.
The BSI report on multiple TeamViewer vulnerabilities does not contain CVE IDs or information on active exploitation, making prioritization difficult.
The BSI advisory bundles multiple vulnerabilities in Ubiquiti UnifiOS that together allow code execution, privilege escalation, and security bypass.
The report provides neither CVE nor CVSS nor exploitation status, so it offers no prioritization beyond a general kernel warning.
The BSI report describes multiple Edge vulnerabilities without CVE IDs; relevant is user interaction (website or Office file) as the exploitation vector.
No changes in this category.
No changes in this category.
The flaw does not defeat a security feature but the user-defined permission boundaries during session establishment , hardened configurations therefore offer no protection, and the bypass can escalate into code execution on the target system.
The report provides no insights beyond pure patch information; there are no indications of active exploitation or new attack techniques.
Pure patch information with no indication of active exploitation or attacker TTPs; the flaw allows code execution within the sandbox and is thus mainly relevant for browser fleets with a delayed update cycle.
The report contains no information beyond the plain CVE description regarding active exploitation or attack campaigns.
The alert contains no indication of active exploitation or attacker TTPs and merely describes a vulnerability in Google Chrome's V8 engine.
The NVD entry provides no indication of active exploitation but describes a critical use-after-free flaw in Chrome that enables sandbox escape and code execution via a crafted HTML page.
The report only provides the critical vulnerability and patch status for Google Chrome, with no indication of active exploitation, specific attackers, or affected sectors.
The report contains no indication of active exploitation, exploit code, or attribution to threat actors; it describes only the vulnerability and the patch.
No evidence of active exploitation; pure vulnerability disclosure without strategic implications.
The report contains no details beyond the patch information, in particular no indications of active exploitation, threat actor groups, or specific victim sectors.
The report adds no information beyond the patch itself; there are no indications of active exploitation or new attack techniques.
The report contains no details beyond the pure patch information regarding active exploitation or attackers.
The report contains no evidence of active exploitation, victim groups, or TTPs; it is limited to a medium-severity Chrome vulnerability requiring an already compromised renderer process.
The critical use-after-free in WindowDialog allows a sandbox escape via social engineering and a crafted HTML page, which goes beyond a pure patch note.
The report contains no details beyond the patch information; there are no indications of active exploitation or a public exploit.
The report provides no indication of active exploitation or an attack campaign; it solely describes the vulnerability and the patch.
Pure patch information with no indication of active exploitation, exploit code, or KEV listing; neither attacker TTPs nor affected sectors are named.
The report provides no information beyond the CVE description and patch requirement, such as active exploitation, exploit code, or specific threat actors.
Beyond the pure patch information, it is notable that exploitation requires social engineering and allows escape from the browser sandbox, pointing more to targeted attacks than mass propagation.
The report contains no information beyond the patch details indicating active exploitation or attacker TTPs.
The report provides no evidence of active exploitation or an attack campaign and thus goes no further than the pure patch information.
Pure patch information with no indication of active exploitation, PoC, or attacker TTPs , the flaw in the V8 engine allows code execution inside the sandbox and is therefore primarily a prompt-patching matter.
The report describes a vulnerability without indications of active exploitation or attacker TTPs.
The report reveals a concrete identity takeover vulnerability in self-hosted Bitwarden Server with SQL Server and SSO, going beyond a patch note because it enables authentication as another organization member.
The report documents a new malware delivery technique Microsoft tracks as RedFlick, plus large-scale abuse of compromised website accounts by a Russian state actor , an evolution in detection evasion rather than just another patch story.
Star Blizzard relies on volume and a single victim interaction to compromise cloud accounts and is expanding targets beyond Ukraine.
Microsoft documents a previously unknown China-APT malware framework (NeedyMantis) that maintains long-term access in compromised networks , indicating sustained state-sponsored persistence campaigns, not just a single exploit.
The case shows that state actors continue to rely on compromised legitimate sender accounts and convincing social-engineering invitations rather than technical exploits; the Microsoft attribution provides concrete TTPs for detection.
Beyond the plain patch information, the report shows that exploitation requires pre-existing local access or an authenticated session, so the flaw is only practically relevant as an escalation step after prior compromise.
The report provides no evidence of active exploitation or attack campaigns; it describes a local vulnerability requiring user interaction.
The flaw lets a locally logged-on attacker exploit a timing gap in the rollback mechanism to execute with SYSTEM privileges and thus fully compromise the endpoint.
No insights beyond the pure patch information; no active exploitation or strategic relevance known.
This report describes a novel Windows LPE technique via dangling COM registrations and shows that the fix for CVE-2026-50343 was incomplete.
This report contains no information beyond the patch itself about active exploitation or strategic relevance.
The CVE entry provides only the technical description of the vulnerability; there is no indication of active exploitation or attack context.
This report contains no details beyond the pure patch information; there is no indication of active exploitation.
The report contains no details beyond the pure patch information.
The report shows that the vulnerability is only exploitable after the renderer process has already been compromised and contains no indication of active exploitation.
The report provides no indication of active exploitation or additional TTPs and is limited to the vulnerability description.
No insights beyond the patch information; the report contains no evidence of active exploitation or strategic relevance.
Abusing GPOs allows ransomware operators to propagate domain-wide and centrally disable Defender settings, bypassing classic endpoint protection measures.
The BSI advisory describes a bypass of security safeguards in Bitwarden by a remote authenticated attacker, without a CVE reference or indication of active exploitation.
The report contains no indication of active exploitation, specific victims, or attacker TTPs and thus does not go beyond plain patch information.
The report contains no information about active exploitation or attack campaigns; it is purely a low-severity vulnerability description.
Pure NVD entry for a low-severity vulnerability in Google Chrome; no indication of active exploitation or an attack campaign.
The report contains no information beyond the pure CVE description, in particular no indication of active exploitation or strategic relevance.