CVE-2025-66376

mediumpriority · act · 90OT risk · criticalKEV · exploitedEPSS 0.202 · 97 %ileDEEURUUS

grimoire priorityP0 · Act now

Exploitable?

Yes · in the wild

CISA KEV

Likely / severe?

20.2% (97th) EPSS

CVSS 6.1 · medium

Is it mine?

10 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

added 2026-03-18remediate by 2026-04-01

required action Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

EPSS · scored 2026-10-22

Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting Vulnerability

Zimbra Collaboration (ZCS) 10 before 10.0.18 and 10.1 before 10.1.13 allows Classic UI stored XSS via Cascading Style Sheets (CSS) @import directives in an HTML e-mail message.

cvss

Technical severity, 0–10. One row per scoring source.

7.2

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.1–7.2

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nprimary · NVD / NIST USexploitability 2.8 · impact 2.7

v3.17.2highAV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:Nsecondary · FSTEC (BDU) RU

v3.17.2highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:Nsecondary · ENISA EU

v3.17.2highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:Nsecondary · cve@mitre.org USexploitability 3.9 · impact 2.7

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:Hsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: active · Automatable: no · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-79USCWE-79US

affected products (10)

Products and version ranges known to be affected.

Synacor Zimbra <10.0.18all versionscert_bundDE
Synacor Zimbra <10.1.13all versionscert_bundDE
Synacor Zimbra< 10.0.18cert_bundDE
Synacor Zimbra< 10.1.13cert_bundDE
Zimbra Collaboration10.0 → 10.0.18enisa_euvdEU
Zimbra Collaboration10.1 → 10.1.13enisa_euvdEU
Zimbra Inc. Zimbra Collaboration Suite10.0.0 → 10.0.18fstec_bduRU
Zimbra Inc. Zimbra Collaboration Suite10.1.0 → 10.1.13fstec_bduRU
synacor zimbra collaboration suite10.0.0 → 10.0.18nvdUScpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*
synacor zimbra collaboration suite10.1.0 → 10.1.13nvdUScpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2025-2911Synacor Zimbra: Mehrere SchwachstellenDeutsch2025-12-22csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Synacor Zimbra ausnutzen, um einen Cross-Site Scripting Angriff durchzuführen, um Sicherheitsvorkehrungen zu umgehen, und um beliebigen Programmcode auszuführen.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund nvd NVD CVE.org MITRE

published 2026-01-05modified 2026-06-17

references (18)

External citations — patches, advisories, analysis.

scry

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