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CVE-2026-50053

Zimbra Collaboration Suite RestFilter Request Attribute Override via Unauthenticated URL Parameters

CVSS score

8.7

EPSS probability

—

Risk score

0.9

Published

2 h ago

Patch status has not yet been verified

Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.

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Vulnerability description

DayBreach AI Explanation

Verified against sources

Zimbra Collaboration Suite RestFilter Request Attribute Override Vulnerability

Sources read

2

Source agreement

Tam uyum

Evidence confidence

%61

Short explanation

A request attribute override vulnerability in Zimbra Collaboration Suite allows unauthenticated requests to /h/* to populate servlet attributes intended for trusted internal dispatch. When combined with CVE-2026-10632, it can lead to JavaScript execution in user sessions.

Why does it matter?

This vulnerability allows attackers to bypass identity boundaries and impact other user sessions. Patch availability and security status remain uncertain.

What should be done?

  • Follow official vendor advisories
  • Apply Zimbra Collaboration Suite updates
  • Refer to vendor documentation guidance
Note on uncertainty

The sources give limited detail on some technical conditions. Review the chain of evidence below before deciding how to act.

Chain of evidence and sources3 verified claims

Zimbra Collaboration Suite ürünündeki açık, kimlik doğrulaması yapılmamış isteklerin servlet niteliklerini doldurmasına izin verir.

CVE-2026-10632 ile birleştirildiğinde diğer kullanıcıların oturum açmış tarayıcı oturumlarında JavaScript çalıştırılmasına olanak tanır.

ZCS 10.1.17 sürümü belge oluşturucusunu değiştirerek XSS zincirini engeller ancak istek niteliği geçersiz kılmayı korur.

Show the technical text from the sources

A request attribute override vulnerability in Zimbra Collaboration Suite (ZCS) allows unauthenticated requests to /h/* to populate servlet attributes intended for trusted internal dispatch. RestFilter copies URL parameters specifying an authentication token, target account, target item and dispatch state into the request attributes consumed by the Classic Web Client. Combined with CVE-2026-10632 on ZCS 10.1.16, this allows an attacker to supply their own valid token and document identifiers and execute JavaScript in another user's signed-in browser session. ZCS 10.1.17 blocks that XSS chain by changing the document renderer, but retains the request attribute override.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

CWE: CWE-642

This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-50053 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1ZimbraZimbra Collaboration Suite View
Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
8.7CVSS V3_1HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:NCVE CNA
8.7CVSS V31HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:NNVD

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-50053 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-50053 weaknesses.

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsLow
UserGerekiyor

Official Sources and Advisories

CVSS Vector Radar Chart

8.7 / 10
Attack VectorNetworkComplexityLowPrivilegesLowUser Interact.RequiredConfidentialityLowIntegrityHighAvailabilityNone

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow privileges
User Interaction—
Confidentiality (Gizlilik)Low
Integrity (Bütünlük)High
Availability (Erişilebilirlik)None

Yama durumu bilinmiyor

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Follow the vendor

Z
Zimbra logo
Zimbra

Weakness Type (CWE & CAPEC)

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CVE-2026-50053 · Zimbra Collaboration Suite RestFilter…