A defender-oriented look at detecting indirect prompt injection in MCP-mediated and tool-calling agent stacks: which gateway fields matter, what the first week of alerting looks like, and where most detection programs miss the actual trust boundary.
CVE-2026-42897 is an actively exploited OWA cross-site-scripting flaw in Microsoft Exchange Server 2016, 2019, and Subscription Edition. CVSS 8.1, KEV-listed, federal remediation deadline May 29. A specially crafted email runs JavaScript in the victim’s OWA session — session token theft, mailbox read, send-as, mailbox rules — and the catch buried in Microsoft’s guidance is that a permanent patch is gated behind Period 2 ESU enrollment for everyone still on 2016 or 2019. The EEMS mitigation works, with caveats. Here’s what’s real about it.
A defender’s view of the Famous Chollima / Nickel Tapestry IT worker scheme as it looks in 2026 — the telemetry that actually catches it, the false positives that swamp you in week one, and where it sits in the 800-53 catalog.
TeamPCP — the supply-chain crew behind the Trivy / Checkmarx / KICS / LiteLLM compromises and the Shai-Hulud worm — surfaced a sale listing on May 19, 2026 claiming roughly 4,000 GitHub private repositories of internal source code. The claim is pending verification, the ESIX score is 7.96, and the group’s track record is exactly the mix of ‘demonstrably capable’ and ‘inclined to repackage’ that makes this kind of listing operationally annoying. Here’s the read.
A defender-side look at where PRC pre-positioning campaigns against critical infrastructure stand heading into 2026, what living-off-the-land actually looks like in the SIEM, and which tuning calls separate the teams that catch it from the teams that don’t.
Image-mode RHEL and bootc move /usr to a read-only ostree commit and turn host updates into container pulls. That fixes one class of problem and creates a different one for defenders. Here is what actually changes on disk, what to detect, and where the model breaks.
A defender-oriented look at where HTTP/2-to-HTTP/1.1 request smuggling sits in 2026 — the parser-differential class that keeps finding new homes, what the detection actually looks like in Splunk, and what most teams miss on the first tuning pass.
Device Bound Session Credentials are landing in Chrome and Edge, but the gap between the protocol promise and what your SIEM sees is wider than the vendor decks suggest. A defender-oriented look at what detection actually requires right now.
ClickFix initial access has been pasting PowerShell into RunMRU for two years and most detection content still treats it like a primer. Here is what the telemetry actually looks like, what tunes out, and where teams keep getting it wrong.
A defender-oriented analysis of indirect prompt injection in tool-calling agents: where the signal actually lives in the trace pipeline, what the first week of tuning has to fix, and which 800-53 controls the implementation maps to.
