CVE-2026-33370Disclosure(synacor / zimbra_collaboration_suite)

LOWCVSS 6.1 · MEDIUM

Exploitation ongoing with high activity in latest observed window (1 mentions)

Immediate actions

Prioritize remediation for synacor zimbra_collaboration_suite systems immediately
Assume compromise if assets are exposed
Track advisory updates for patch or workaround availability

Recommended action window: Immediate (within 24h)

NVD description

An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. A stored cross-site scripting (XSS) vulnerability exists in the Zimbra Briefcase feature due to insufficient sanitization of specific uploaded file types. When a user opens a publicly shared Briefcase file containing malicious scripts, the embedded JavaScript executes in the context of the user's session. This allows an attacker to run arbitrary scripts, potentially leading to data exfiltration or other unauthorized actions on behalf of the victim user.

synacor CVEs Back to dashboard

3.5/ 10 priority

Sources & remediation

Vendor / third-party advisories

Other references

Weakness type (CWE)

CWE-79

Priority

LOW

Exploitation

ACTIVE

PoC

NONE

Patch

NONE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

zimbra_collaboration_suite

Threat summary

Active exploitation appears in 1 classified signals
2 mentions across 2 observed days
Momentum state: stable

What's happening

Active exploitation reported across 1 signal
Technical details provided in 2 signals
Disclosure: 1 classified signal
Peaked 1d ago at 1 mentions (2026-03-22); latest day: 1
2 total mentions across 2 days

Affected systems

Vendors

synacor

Products

zimbra_collaboration_suite

Deep dive

Activity timeline2 mentions / 2d

Signal classification2 categories

Disclosure

150.0%

Active Exploitation

150.0%

Referenced assets2 URLs

By indicator

Classification over time

Date	Total	Labels

2026-03-22	1	Disclosure1
2026-07-11	1	Active Exploitation1

Full discourse2 posts

Aviatrix Threat Research Center@aviatrixtrc89d
Active Exploitation
Attackers exploited CVE-2026-33370 to inject malicious JavaScript into Zimbra's Briefcase feature, enabling session hijacking and potential lateral movement within corporate networks. Runtime segmentation helps limit post-compromise expansion when web applications are breached. #CloudSecurity 🔗 Full TRC analysis: https://aviatrix.ai/threat-research-center/zimbra-stored-xss-vulnerability-2026
Post summary
The post reports that attackers are actively exploiting CVE-2026-33370 in Zimbra’s Briefcase via malicious JavaScript to hijack sessions and move laterally, with runtime segmentation noted as a mitigative measure.
0000154
1.9K followersView on X
CVE@CVEnew200d
Disclosure
CVE-2026-33370 An issue was discovered in Zimbra Collaboration (ZCS) 10.0 and 10.1. A stored cross-site scripting (XSS) vulnerability exists in the Zimbra Briefcase feature due to i… https://www.cve.org/CVERecord?id=CVE-2026-33370
Post summary
A stored XSS issue was identified in Zimbra Collaboration 10.0 and 10.1's Briefcase feature; no PoC, exploit, patch, or active exploitation details are included.
00000179
56.8K followersView on X

CPE platform detail1 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

1 of 1 entries

Part	Vendor	Product	Version	Target SW	Target HW
App	synacor	zimbra_collaboration_suite	-	-	-

Explore more

Back to dashboard synacor CVEs zimbra_collaboration_suite vulnerabilities