How severe is CVE-2018-6882?

CVE-2018-6882 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2018-6882?

Affected package information for CVE-2018-6882 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2018-6882?

No fixed version has been published for CVE-2018-6882 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2018-6882 actively exploited in the wild?

Yes. There are 4 known exploit references for CVE-2018-6882, including 4 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2018-6882?

CVE-2018-6882 has an EPSS (Exploit Prediction Scoring System) score of 77.0%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2018-6882 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2018-6882 (Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-04-19. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-10. The required action was: Apply updates per vendor instructions. This CVE has been used in known ransomware campaigns. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2018-6882?

CVE-2018-6882 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Is there exploit tooling available for CVE-2018-6882?

A Nuclei detection template exists for CVE-2018-6882, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2018-6882 published, and has it been updated?

CVE-2018-6882 was published on March 27, 2018 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2022-04-19 — agencies required to remediate by 2022-05-10 · Ransomware

CVE-2018-6882

MEDIUM

Published

Mar 27, 2018

Updated

Apr 10, 2026

Affected

0 pkgs

Patched

None yet

Exploits

4 known

EPSS Exploitation Probability

via FIRST.org ↗

77.0%probability of exploitation in next 30 days

Very High Risk99th percentile-2.50%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachmentLinkHtml function in Zimbra Collaboration Suite (ZCS) before 8.7 Patch 1 and 8.8.x before 8.8.7 might allow remote attackers to inject arbitrary web script or HTML via a Content-Location header in an email attachment.

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachm…

securify.nlNVDMar 2019

Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachm…

packetstormsecurity.comAPIMar 2018

Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachm…

cert.gov.uaAPIApr 2022

Cross-site scripting (XSS) vulnerability in the ZmMailMsgView.getAttachm…

cisa.govCISAApr 2022

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2018-6882 in your stack?

O3 detects CVE-2018-6882 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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