STAC3725 CitrixBleed 2-to-DragonForce IAB chain

Confirmed in-the-wild exploitation of internet-facing enterprise software converged this week — ColdFusion, Citrix NetScaler and Gitea all moved from 'at risk' to 'under attack'

If you did nothing this week: three classes of internet-facing enterprise software you likely have somewhere in the estate moved from theoretical risk to confirmed exploitation. An unpatched, exposed ColdFusion, Citrix NetScaler Gateway or Gitea instance should be handled as an incident, not a maintenance ticket — and for NetScaler, applying the patch does not evict an attacker who already has your session tokens.

The week's exploitation signal converged on the perimeter. Adobe ColdFusion CVE-2026-48282 — one of the six unauthenticated CVSS 10.0 RCEs Adobe patched on 1 July, and exactly the item last week's outlook flagged as awaiting weaponisation — was confirmed exploited in the wild and added to CISA KEV on 7 July; KEVIntel reported catching exploitation "within under two hours of CVE-2026-48282 public details being released" against its honeypots (BleepingComputer, 2026-07-08). Citrix NetScaler saw the most operationally consequential development: Huntress reconstructed a mechanically identical intrusion chain across at least six unrelated organisations, run by an initial-access broker (Sophos: STAC3725) that steals pre-auth session tokens via CitrixBleed 2 (CVE-2025-5777) — "sift[ing] through the heap fragments for valid session tokens of someone who is currently logged in" (Huntress, 2026-07-10) — then escalating via a registry-symlink privilege-escalation tool to SYSTEM, persisting with ScreenConnect/Zoho Assist, and in the most progressed case deploying DragonForce ransomware. Because the stolen tokens survive patching, remediation requires terminating live sessions as well. Finally, NCSC-CH escalated the Gitea Docker reverse-proxy authentication bypass (CVE-2026-20896) — full unauthenticated admin control "via a single custom HTTP header" — to "Actively Exploited, Proof of Concept Available" (NCSC-CH Cyber Security Hub, 2026-07-10). A fourth strand — Langflow's cross-tenant IDOR (CVE-2026-55255) chained with pre-auth RCE, first exploited 25 June and now KEV-listed (Sysdig, 2026-07-08) — reinforces the same lesson: exploitation, not CVSS, is what set this week's priorities.

Builds on: 2026-07-08/cve-2026-48282-adobe-coldfusion-actively-exploited-kev · 2026-07-10/citrixbleed-2-dragonforce-iab-kill-chain-stac3725 · 2026-07-10/gitea-cve-2026-20896-ncsc-ch-actively-exploited-update · 2026-07-08/cve-2026-55255-langflow-idor-kev-chained-with-rce

CitrixBleed 2 (CVE-2025-5777) weaponised into a repeatable IAB kill chain ending in DragonForce ransomware (STAC3725)

Across the first half of 2026 the Huntress Tactical Response unit worked at least six intrusions at unrelated organisations that reproduced the same seven-step kill chain so faithfully that analysts could predict the next artefact before pulling the log — the basis for their high-confidence assessment that an initial-access broker (IAB) has productised the path from an internet-facing Citrix box to domain-wide encryption, a cluster Sophos independently tracks as STAC3725 (Huntress, 2026-07-09; Sophos X-Ops, 2026-04-16). Initial access is pre-auth exploitation of CitrixBleed 2 (CVE-2025-5777), a memory over-read in NetScaler ADC/Gateway configured as a Gateway or AAA virtual server: a POST to the login endpoint (/p/u/doAuthentication.do and equivalents) with the login form variable present but empty makes the appliance serialise roughly 127 bytes of adjacent process memory into the response, and sprayed at volume this yields live session tokens (T1190, T1550.001). In one reconstructed case a user authenticated normally over LDAP+MFA from a known-good IP at 13:07 UTC; twenty-one minutes later the same session was driven from the attacker's IP with no successful authentication from that IP anywhere in the logs — token replay, with MFA already satisfied and therefore irrelevant (Huntress, 2026-07-09).

The privilege-escalation primitive is what makes the cluster unmistakable, because the hijacked session usually belongs to an unprivileged employee and the operator carries a portable, unsigned LPE tool (dropped to working paths such as C:\temp and renamed per victim — eng.exe, legal.exe, as.exe — often inside a password-protected archive pulled from temp.sh). The tool plants a REG_LINK SymbolicLinkValue under the RdpBus device-class key {28d78fad-5a12-11d1-ae5b-0000f803a8c2} that redirects into the Group Policy state hierarchy (T1112); running gpupdate forces the SYSTEM-context Group Policy engine to write through the planted link into a protected key, and sc start AppMgmt then makes the Service Control Manager relaunch the dropper as NT AUTHORITY\SYSTEM, which creates a backdoor administrator via net user … /add and net localgroup Administrators … /add (T1068, T1136.001, T1098). AppMgmt is chosen because it is always present, normally dormant, and plausibly related to policy processing. Before detonating, the tool snapshots the original key tree and restores it afterwards, leaving the registry indistinguishable from its pre-exploit state to erase the artefacts a responder would key on (T1070). Persistence then rides legitimate remote-management software — ScreenConnect and Zoho Assist, in one case Netbird plus Atera (T1219) — and in the most advanced case the operator used PsExec, Impacket and Mimikatz for lateral movement and credential access (T1003, T1570) before deploying DragonForce ransomware, contained to a single host (T1486). Huntress declines a firm DragonForce-affiliate-versus-IAB attribution given the tactic overlap, and ruled out an alternative NetScaler session-management race-condition flaw because the affected build and the required already-authenticated session to race against did not fit the evidence.