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CVE Record

CVE-2025-40903: HTML injection in Schedule Restore Archive in Guardian/CMC before 26.1.0

A Stored HTML Injection vulnerability was discovered in the Schedule Restore Archive functionality due to improper validation of an input parameter. An authenticated user with administrative privileges can define a malicious restore schedule containing HTML tags. When a victim views the affected schedule, the injected HTML renders in their browser, enabling phishing and possibly open redirect attacks. Full XSS exploitation and direct information disclosure are prevented by the existing input validation and Content Security Policy configuration.

MediumCVSS 5.9Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

An administrator can place HTML into a restore schedule in Nozomi Guardian or CMC before version 26.1.0. Anyone viewing that schedule could see deceptive content supporting phishing or redirection. Existing validation and browser security policy reportedly prevent full script execution and direct data disclosure, limiting—but not eliminating—business risk.

Executive priority

Prioritize normal-cycle remediation, escalating if an affected management interface has weak administrator controls or suspicious schedules. This is not presented as an unauthenticated takeover or confirmed active threat, but trusted-interface phishing can support credential theft and further compromise.

Technical view

CVE-2025-40903 is a stored HTML injection in Schedule Restore Archive caused by improper input validation. Exploitation requires network access, administrative privileges, and a victim viewing the affected schedule. The CVSS 3.1 score is 5.9. Existing validation and Content Security Policy limit full XSS and direct information disclosure.

Likely exposure

Exposure is likely limited to Guardian or CMC versions before 26.1.0 where administrative users can create restore schedules. Risk increases if administrator accounts are compromised, shared, or insufficiently controlled. The supplied affected-version metadata is internally inconsistent, so organizations should confirm applicability against Nozomi's advisory.

Exploitation context

The bundle provides no evidence of active exploitation, and this CVE is not listed as KEV. Abuse requires an authenticated administrator to save malicious HTML and another user to view the schedule. Reported outcomes include phishing and possible open redirects; full XSS and direct disclosure are reportedly blocked.

Researcher notes

The CVSS vector is AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L. The described behavior supports CWE-79 classification, although controls constrain script execution. The bundle's affected entries show version “0” with default status “unaffected,” conflicting with the title's “before 26.1.0”; validate precise product applicability with vendor sources.

Mitigation direction

  • Upgrade affected Guardian and CMC installations to version 26.1.0 or later.
  • Confirm the supported remediation and applicability in Nozomi Networks' advisory.
  • Restrict administrative access to trusted personnel and review privileged accounts.
  • Remove or correct restore schedules containing unexpected HTML.
  • Limit management-interface access to authorized networks where operationally feasible.

Validation and detection

  • Inventory Guardian and CMC installations and record their exact versions.
  • Identify installations running versions earlier than 26.1.0.
  • Review restore schedules for unexpected HTML, links, or deceptive content.
  • Confirm untrusted schedule input no longer renders as HTML after remediation.
  • Review administrative activity for suspicious schedule creation or modification.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-79: User-session and phishing behavior lookup

Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2025-40903 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.9 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
3Timeline events
2ADP providers
3Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
5.9CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L1.73.7Nozomi
4.8CVSS 4.0MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L——Nozomi

Vulnerability scoring details

Base CVSS 4.0 score

4.8Medium
CVSS 4.0 vector shape for CVE-2025-40903Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
siemens-SADPADP container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Nozomi NetworksGuardian0unaffected
Nozomi NetworksCMC0unaffected
Weakness

CWE details

CWE-79

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-79 · source CWE mapping

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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