5SEP

Patch Tuesday clean streak hides out-of-band KEVs

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12:09UTC

Microsoft's 13 May Patch Tuesday shipped 120 CVEs with no zero-days exploited in the wild, breaking what would have been a 22-month streak since July 2024. Two out-of-band KEV additions inside 48 hours reset the picture.

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Key takeaway

Two out-of-band KEVs in 48 hours show Patch Tuesday is no longer the reliable cadence.

Microsoft released its May 2026 Patch Tuesday on Wednesday 13 May with 120 CVEs addressed and no zero-days exploited in the wild, breaking a 22-month streak in which every Patch Tuesday since July 2024 had contained at least one zero-day⁠¹⁠². BleepingComputer, which tracks the monthly cycle alongside Microsoft Security Response Center disclosures, recorded the gap as the first scheduled release in the streak without an actively exploited flaw.

The headline broke before the picture settled. Within 48 hours of the release, CISA added two further CVEs to the Known Exploited Vulnerabilities catalogue outside the scheduled window: CVE-2026-20182 in Cisco SD-WAN on Thursday 14 May, and CVE-2026-42897 in Exchange Server's Outlook Web Access on Friday 15 May. Both were actively exploited; only the Cisco flaw had a vendor patch. The Exchange addition mirrored the Palo Alto out-of-band pattern that opened May and ran alongside the Microsoft LSASS out-of-band fix issued in April.

For security operations Teams, the signal-quality question matters. Patch Tuesday was the predictable artefact around which monthly vulnerability-management work was scheduled. A clean Patch Tuesday next to two out-of-band KEVs within two days does not show improved vendor security posture; it shows that the exploitation timeline has decoupled from the scheduled release. The defensive cadence assumption (a 30-day cycle around the second Tuesday of each month) no longer maps to where the urgent disclosures actually arrive. Federal civilian agencies remain bound by Binding Operational Directive 22-01 regardless of when the KEV addition lands, and the Trump administration's FY27 proposal to cut CISA by $707 million does not change the issuance tempo, only the agency's capacity to enforce it.

Deep Analysis

In plain English

On 13 May 2026, Microsoft released its monthly security fixes covering 120 flaws, and for the first time in nearly two years there were no emergency patches for flaws hackers were already using. But within two days, US security authorities added two urgent flaws to their watch list: one in Cisco software and one in Microsoft's own email server.

Source Landscape

This story draws on neutral-leaning sources

Primary parallel: Microsoft's October 2023 Patch Tuesday, which included a zero-day-free release that was similarly followed within days by emergency out-of-band fixes for actively exploited flaws in third-party products. The pattern of a clean scheduled release alongside an out-of-band burst is recurrent rather than exceptional, and the 2026 case follows the same structure.

Counter-parallel: The July 2024 Patch Tuesday that started the 22-month streak contained CVE-2024-38112, a zero-day in Windows MSHTML exploited by APT groups before disclosure. That release established the baseline against which May 2026's clean release is measured.

The two Patch Tuesdays share the same metric framework but represent opposite outcomes within it, illustrating that the metric itself is stable while attacker targeting and vendor disclosure timing continue to shift independently.

Consensus view: Recorded Future's vulnerability intelligence team and BleepingComputer's patch-tracking data both indicate that the 22-month in-the-wild zero-day streak ending on Patch Wednesday 13 May was a product of Microsoft's improved pre-disclosure co-ordination with vulnerability researchers, not a step-change reduction in the underlying bug rate, since out-of-band KEV additions immediately followed.

Counter-view: Kev Breen at Immersive Labs argues the headline metric, zero zero-days in Patch Tuesday, is structurally misleading: the 120-CVE release included nine critical-severity RCEs, several of which Breen's team assesses as likely exploited before disclosure based on their technical profile. The absence of confirmed in-the-wild exploitation may reflect detection gaps rather than genuine exploitation absence.

Key tension: The 22-month streak is itself a product of Microsoft's decision to announce exploitation status at Patch Tuesday disclosure, a process it controls. Two out-of-band KEV additions within 48 hours, for Cisco and Exchange, show that the exploitation tempo has not changed; only the labelling cadence has, raising the question of whether the streak was an artefact of Microsoft's disclosure process rather than attacker behaviour.

Sources:BleepingComputer·Tenable

Mentions:Microsoft →CISA →Palo Alto Networks →Known Exploited Vulnerabilities →Cisco →Trump administration →CVE-2026-20182 →Outlook Web Access →BleepingComputer →May Patch Tuesday →CVE-2023-50224 →BOD 22-01 →Binding Operational Directive →Patch Tuesday →

First Reported In

Update #4 · AI joins the breach column on both sides

BleepingComputer· 20 May 2026

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Causes and effects

This Event

Patch Tuesday clean streak hides out-of-band KEVs

The Patch Tuesday metric has stopped being a reliable signal of vulnerability disclosure tempo. Exploitation has migrated from the scheduled release cycle to the out-of-band window where defenders have less notice.

Led to

200 fixes, six zero-days, late Exchange

May Patch Tuesday's 120-CVE zero-zero-day release broke a 22-month streak; June's 200-CVE six-zero-day reversal is a direct contrast used to frame the magnitude of the month's patch burden.

Occurred 9 Jun 2026

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Different Perspectives

Hospital Sírio-Libanês

Hospital Sírio-Libanês said a 21 September attack reached a reporting system for its social projects, possibly exposing patients' and staff identity numbers and health information, while its general patient database was untouched. It notified the ANPD and the Polícia Federal and warned of fraud attempts.

The Foschini Group

The Foschini Group told the Johannesburg exchange on 13 October that an attack found on 11 October disrupted IT systems at its TFG London brands, while stores stayed open. It has not identified the attackers or established whether personal data was taken.

FirstVDS

FirstVDS said attackers used a VMmanager 6 flaw to copy customers' passwords, cloud credentials and cryptocurrency wallets from beneath their virtual servers, and told notified customers to assume theft and rotate credentials. ISPsystem's flaw was not fully fixed on 19 October.

ESET

ESET says Russia-aligned UAC-0099 phished a Ukrainian grain logistics firm in July 2025 and apparently passed its access to GRU-linked Sandworm, which wiped the company's data that September. It treats the attackers' use of the Yggdrasil network as a first for a state-aligned actor.

JPCERT/CC

JPCERT/CC issued emergency alert AT-2026-0032 on 14 October as EG Secure Solutions confirmed attacks on the SiteGuard Server Edition flaw. It told operators to save diagnostic data before updating, because the update may erase traces of the attack.

Cyber Security Agency of Singapore

The Cyber Security Agency of Singapore said on 20 October that attackers are exploiting Ivanti Connect Secure, seven days after Ivanti's disclosure, having flagged PAN-OS exploitation on 16 October. It issued a PHP2Shell alert on 21 October, the day the fixes shipped.

Written with AI from Lowdown's published reporting. Not individually reviewed by an editor. Editorial standards.