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Apexward Pulse
Type Vulnerability

Synacor Zimbra Collaboration Suite (ZCS)

Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability

3 sourcesCVE-2025-27915CVE-2022-27925CVE-2025-48700+4 more

At a glance

Medium
7-day window, from the last update
ActiveConfirmed in-the-wild exploitation
Evidence-weighted, not popularity
Signal

Actively exploited in the wild — prioritise confirming exposure.

Why Medium

Medium rather than High: exposure is scored at a default because we cannot see your systems or suppliers. If you run or depend on Synacor Zimbra Collaboration Suite (ZCS), treat it as High.

Briefing

  • Do not treat uncorroborated claims as confirmed breaches.

Questions to ask IT

  • Do we run Synacor Zimbra Collaboration Suite (ZCS), and which versions?
  • Is any of it reachable from the internet?
  • Have we checked whether it has already been used against us?
  • If it is not yet patched, what mitigation is in place, and will the fix be done by 12 Nov?

Next steps

  1. Confirm exposure and remediation status for affected products

Summary

  • Business Email Compromise (BEC) operates on a familiar playbook. Threat actors breach a mailbox, silently monitor operations, map approval chains, and ultimately exploit that access to divert funds or exfiltrate sensitive assets.
  • CVE-2022-27925 is confirmed as exploited in the wild (US known-exploited catalogue)
  • CVE-2022-27925 has an estimated ~98.7% chance of attack in 30 days (99.9th percentile) as of 2026-09-23 — probability signal, not confirmed exploitation
  • CVE-2023-37580 is confirmed as exploited in the wild (US known-exploited catalogue)

Read the original reportThe Register Security(opens in a new tab)

Products and services involved

Same event, different frames

Distinct often headline the same incident differently.

Pulse

Last checked 3d ago · Recheck overdue since 6 Nov 2026, 07:37 UK time

Update
5 Nov 2026, 07:37 UK time · 3d ago

held at 99.9%; ranking metadata was updated.

Listed on the — prioritise confirming exposure and patching.

EscalationDe-escalationCritical / liveWhat these mean
Drag to pan · Ctrl / ⌘ + scroll or pinch to zoom12 events

1 quiet check hidden.

Sources

How we know

Statements extracted from sources. Higher confidence means stronger corroboration.

  • ClaimedHeadline60% confidence

    Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload Vulnerability

  • ProbableSummary fact75% confidence

    Business Email Compromise (BEC) operates on a familiar playbook. Threat actors breach a mailbox, silently monitor operations, map approval chains, and ultimately exploit that access to divert funds or exfiltrate sensitive assets.

  • ConfirmedCVE identifier95% confidence

    Event involves CVE-2022-27925

  • ConfirmedKnown-exploited catalogue98% confidence

    CVE-2022-27925 is confirmed as exploited in the wild (US known-exploited catalogue)

  • ConfirmedEstimated attack likelihood95% confidence

    CVE-2022-27925 has an estimated ~98.7% chance of attack in 30 days (99.9th percentile) as of 2026-09-23 — probability signal, not confirmed exploitation

  • ConfirmedCVE identifier95% confidence

    Event involves CVE-2022-37042

  • ConfirmedKnown-exploited catalogue98% confidence

    CVE-2022-37042 is confirmed as exploited in the wild (US known-exploited catalogue)

  • ConfirmedCVE identifier95% confidence

    Event involves CVE-2023-37580

  • ConfirmedKnown-exploited catalogue98% confidence

    CVE-2023-37580 is confirmed as exploited in the wild (US known-exploited catalogue)

  • ConfirmedCVE identifier95% confidence

    Event involves CVE-2024-45519

  • ConfirmedKnown-exploited catalogue98% confidence

    CVE-2024-45519 is confirmed as exploited in the wild (US known-exploited catalogue)

  • ConfirmedEstimated attack likelihood95% confidence

    CVE-2024-45519 has an estimated ~99.9% chance of attack in 30 days (100th percentile) as of 2026-09-23 — probability signal, not confirmed exploitation