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Full vulnerability report · 2026
CVE-2025-12776High confidence

Stored Cross-Site Scripting

Commvault · WebConsole

1.8LowCVSS 4.0
Recommended action
Scheduled

Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityLowOperational priority:Low, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.18% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Commvault WebConsole and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: No default targetRemediation target: Normal maintenance

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2025-206259

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Low technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

The Report Builder component of the application stores user input directly in a web page and displays it to other users, which raised concerns about a possible Cross-Site Scripting (XSS) attack. Proper management of this functionality helps ensure a secure and seamless user experience.  Although the user input is not validated in the report creation, these scripts are not executed when the report is run by end users. The script is executed when the report is modified through the report builder by a user with edit permissions. The Report Builder is part of the WebConsole.  The WebConsole package is currently end of life, and is no longer maintained. We strongly recommend against installing or using it in any production environment. However, if you choose to install it, for example, to access functionality like the Report Builder, it must be deployed within a fully isolated network that has no access to sensitive data or internet connectivity. This is a critical security precaution, as the retired package may contain unpatched vulnerabilities and is no longer supported with updates or fixes.

What

The Report Builder component of the application stores user input directly in a web page and displays it to other users, which raised concerns about a possible Cross-Site Scripting (XSS) attack. Proper management of this functionality helps ensure a secure and seamless user experience.  Although the user input is not validated in the report creation, these scripts are not executed when the report is run by end users. The script is executed when the report is modified through the report builder by a user with edit permissions. The Report Builder is part of the WebConsole.  The WebConsole package is currently end of life, and is no longer maintained. We strongly recommend against installing or using it in any production environment. However, if you choose to install it, for example, to access functionality like the Report Builder, it must be deployed within a fully isolated network that has no access to sensitive data or internet connectivity. This is a critical security precaution, as the retired package may contain unpatched vulnerabilities and is no longer supported with updates or fixes.

Why

Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

The Report Builder component of the application stores user input directly in a web page and displays it to other users, which raised concerns about a possible Cross-Site Scripting (XSS) attack. Proper management of this functionality helps ensure a secure and seamless user experience.  Although the user input is not validated in the report creation, these scripts are not executed when the report is run by end users. The script is executed when the report is modified through the report builder by a user with edit permissions. The Report Builder is part of the WebConsole.  The WebConsole package is currently end of life, and is no longer maintained. We strongly recommend against installing or using it in any production environment. However, if you choose to install it, for example, to access functionality like the Report Builder, it must be deployed within a fully isolated network that has no access to sensitive data or internet connectivity. This is a critical security precaution, as the retired package may contain unpatched vulnerabilities and is no longer supported with updates or fixes.

Why

Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
High: elevated access is required
User interaction
Active interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-79 ↗

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UIActiveUser interaction: A user must take a deliberate action for exploitation to succeed.VCLowVulnerable-system confidentiality: A successful attack can cause a limited loss.VILowVulnerable-system integrity: A successful attack can cause a limited loss.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkCWE-79
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

Cyber Security Agency of Singapore · English · CSA-SB-20260114Security Bulletin 14 Jan 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 14 Jan 2026, published on 14 January 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-002598Commvault Systems, IncのCommvaultにおけるクロスサイトスクリプティングの脆弱性

アプリケーションのレポートビルダーコンポーネントは、ユーザー入力を直接ウェブページに保存し、他のユーザーに表示するため、クロスサイトスクリプティング(XSS)攻撃の可能性が懸念されています。この機能を適切に管理することは、安全でシームレスなユーザー体験を確保するのに役立ちます。レポート作成時にはユーザー入力の検証が行われませんが、最終ユーザーがレポートを実行する際にはこれらのスクリプトは実行されません。スクリプトは編集権限を持つユーザーがレポートビルダーでレポートを修正する際に実行されます。レポートビルダーはWebConsoleの一部です。WebConsoleパッケージは現在サポート終了(EOL)しており、もはやメンテナンスされていません。運用環境でのインストールや使用は強く推奨されません。ただし、例えばレポートビルダーの機能にアクセスするためにインストールする場合は、機密データやインターネット接続を一切含まない、完全に隔離されたネットワーク内で展開しなければなりません。これは重要なセキュリティ対策です。廃止されたパッケージには未修正の脆弱性が含まれている可能性があり、更新や修正のサポートを受けられないためです。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
WebConsole: 11.32.0 ≤ 11.32.*, 11.36.0 ≤ 11.36.*
Fixed
WebConsole: 11.40.1 ≤ 11.40.*, 11.42.1 ≤ 11.42.*
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 7 Jan 2026 · Last source change 8 Jan 2026, 18:17 UTC · CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2025-206259
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2025-12776 · cve.blacktree.nl