Someone has spent more than a year rifling through Salesforce and ServiceNow portals around the world, harvesting data that organizations accidentally left open to anyone who came looking. Researchers at Reco have named the operation "City-Forum" after a domain connected to its infrastructure. The domain has pointed to the attacker's server since March 2025, although exactly when the campaign began is unclear. Reco says the activity is continuing and increasing in volume. Reco isn't naming the targets, but said it spotted the attacker poking around portals belonging to telecoms companies, banks and other financial services firms, enterprise software vendors, cybersecurity companies, and public sector bodies. "In the last year, we've seen many threat actors that use Aura enumeration against over-permissioned Salesforce guest users. This actor is different," said Nitay Bachrach, senior security researcher at Reco. On Salesforce, the attacker targets Lightning Web Runtime (LWR) sites through the UI API's GraphQL layer, an approach Reco says it has not found documented in public research or incorporated into publicly available attack tools. Over at ServiceNow, the same operator queries a native Service Portal search endpoint that has received little public attention. The tooling also checks whether Salesforce sites permit self-registration, potentially offering a route from anonymous guest access to an authenticated external account with permission to see considerably more data. Reco said it saw these checks across most of the Salesforce targets it examined. "The threat actor created their own toolset, based on research and techniques which are not well documented online," Bachrach said. "They studied the services to map different common data leak vectors – this is an advanced actor." This isn't casual poking around either. Reco said the busiest Salesforce target logged more than 560,000 events from the attacker's IP during the campaign, almost all attempts to enumerate data available to guest users. Reco linked the Salesforce and ServiceNow activity to the same server, which targeted multiple organizations around the world. More unusually, the attacker hasn't bothered changing its infrastructure: the same IP address and domain have remained in use for at least 17 months, with related custom tooling doing the rounds across both platforms. ServiceNow told us it is "aware of a security company’s blog post claiming certain configurations are creating security risk. As noted in the security company’s post, there are no allegations of a compromise of the ServiceNow environment. Nonetheless, we take third party reports seriously and are investigating accordingly. Our priority is to protect our customers, their data, and our systems." Salesforce has not yet responded to The Register's questions. Salesforce customers have already had one very public lesson in what can happen when guest access gets too generous. In March, ShinyHunters told The Register it had stolen data from around 100 high-profile companies and nearly 400 websites after going after over-permissioned Experience Cloud guest accounts. City-Forum isn't doing quite the same thing, and Reco isn't blaming ShinyHunters. "We don't know who this is, and we're not ruling anyone in or out," Bachrach said. Reco says all the activity it observed was conducted without authentication, with the attacker collecting information that organizations had exposed through permissions, sharing rules, search sources, or other configuration choices. "If the guest can read a record, so can anyone on the internet," Bachrach warned. "That is not a platform vulnerability." Which is good news for Salesforce and ServiceNow, perhaps, but rather less comforting for anyone now wondering what their guest account has been showing the guests. ®

Nightmare Eclipse, the serial zero-day hunter who has an axe to grind with Microsoft, published a new Defender zero-day, ShieldBreak, that apparently bypasses Redmond’s RoguePlanet patch (CVE-2026-50656), allowing attackers to gain SYSTEM privileges on fully patched Windows 10, Windows 11, and Windows Server systems. According to at least one other researcher, the exploit works. “I've tried it, it works on latest Windows 11,” former Microsoft employee and security expert Kevin Beaumont said. Beaumont also published three detections and hunting queries for ShieldBreak to help defenders rapidly find any stealthy threats. So until Microsoft fixes this latest zero-day, we’d highly suggest using these queries. ShieldBreak is the 10th zero-day from Nightmare Eclipse since they began their scorched-earth strategy against Microsoft in early April. The prolific bug finder and exploit developer is suspected to be a former, very disgruntled, Microsoft employee. And in typical fashion, this latest zero-day drop occurred just hours after Redmond’s monthly Patch Tuesday that fixed 421 security problems in its products - but ShieldBreak isn't one of them. It’s a local privilege-escalation exploit that, according to Nightmare, allows attackers to gain SYSTEM-level privileges. “The PoC was tested in the latest version of windows 11 25h2 (+Canary channel) and windows server 2025, the PoC also have a 100% success rate. Please note that Windows 10 (and respective server editions) are not currently supported, they are however vulnerable to ShieldBreak as well,” they said. While Nightmare claims that the new exploit is a patch bypass for the earlier RoguePlanet vulnerability, CVE-2026-50656, which Microsoft quietly fixed in July, Beaumont pointed out that the two flaws operate very differently. “RoguePlanet was a filesystem race condition vuln that uses virtual disks and NT native file manipulation to trick quarantine process into overwriting system files,” he posted. “ShieldBreak user-mode callback hook to change file contents during a Defender cloud-hydration scan via cfapi (Cloud Filter API).” A Microsoft spokesperson told us the company "is aware of the reported vulnerability and is actively investigating the validity and potential applicability of these claims." The spokesperson added: "Microsoft is committed to investigating security issues and updating impacted products to protect customers as soon as possible. Importantly, we support coordinated vulnerability disclosure, an industry standard that protects customers and supports the research community by ensuring their findings are thoroughly investigated and addressed before being made public." This latest zero-day comes a month after Nightmare Eclipse published its previous vulnerability along with partial exploit code. Nightmare’s July drop, called LegacyHive, is a local privilege escalation flaw that targets Windows’ user hives - the section of the Windows Registry that stores a user's specific desktop settings, application preferences, and environment configurations. It's patched with CVE-2026-62832. There's also a June zero-day called GreatXML that Nightmare developed. The researcher claims the flaw allows a local attacker with administrator rights to bypass BitLocker encryption by manipulating the Windows Recovery Environment. But it has been patched with CVE-2026-50661. The prolific zero-day hunter’s earlier seven Windows bugs do have patches. These include BlueHammer (CVE-2026-33825), RedSun (CVE-2026-41091), UnDefend (CVE-2026-45498), YellowKey (CVE-2026-45585), GreenPlasma (CVE-2026-45586), MiniPlasma (CVE-2020-17103), and RoguePlanet (CVE-2026-50656). After threatening legal action against Nightmare Eclipse in May, and then facing rapid backlash from just about every other security researcher on the planet, Microsoft walked back its talk of siccing its Digital Crimes Unit on people who don’t follow its vulnerability disclosure rules.® Correction: There are patches for GreatXML and Legacy Hive.