Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-27655 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Zohocorp Manageengine Exchange Reporter Plus. Its CVSS base score is 7.3 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 42th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-27655 is a stored cross-site scripting (XSS) vulnerability, classified under CWE-79, affecting Zohocorp ManageEngine Exchange Reporter Plus versions prior to 5802. The flaw resides specifically in the "Permissions Based on Mailboxes" report feature, where untrusted input is not properly sanitized, allowing malicious scripts to be stored and later executed in users' browsers. The vulnerability received a CVSS v3.1 base score of 7.3 (AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N), indicating high severity due to its potential for significant confidentiality and integrity impacts.
An attacker requires low-privileged access (PR:L) to the affected application over the network (AV:N) with low attack complexity (AC:L). By injecting a malicious payload into the Permissions Based on Mailboxes report, the attacker can store XSS that executes when a higher-privileged or unsuspecting user views the report, requiring user interaction (UI:R). Successful exploitation enables high-impact confidentiality breaches, such as session hijacking or data theft, and integrity violations like account takeover or unauthorized actions, without affecting availability.
Mitigation details are outlined in the vendor advisory at https://www.manageengine.com/products/exchange-reports/advisory/CVE-2026-27655.html, which was published alongside the CVE on 2026-04-03. Security practitioners should upgrade to version 5802 or later, as affected versions before this release remain vulnerable to exploitation.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-18631
Vulnerability Data
Zohocorp ManageEngine Exchange Reporter Plus versions before 5802 are vulnerable to Stored XSS in Permissions Based on Mailboxes report.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.1.2V1.3.2
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover missing or incorrect input neutralization through targeted web-application tests.
Input validation directly enforces neutralization of untrusted data before it reaches web output generation.
Output filtering can catch or sanitize unneutralized script content before it is served to users.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).
Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.
Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.
Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.
Requiring language-specific secure-coding standards and automated scanning during the SDLC catches missing output encoding or improper neutralization of untrusted data before the software reaches production.
Secure-coding standards, SAST scans and removal of insecure code samples together eliminate the failure to neutralize script content that produces cross-site scripting flaws.