CVE Intelligence
High Cross-site scripting

CVE-2026-107303 — JHipster: Generated Applications Allow Stored XSS via Unrestricted Blob ContentType Opened as Same-Origin Blob

JHipster is a development platform to quickly generate, develop, and deploy modern web applications and microservice architectures. Prior to generator-jhipster 9.4.0 and react-jhipster 1.1.0, generated applications can persist attacker-controlled Blob data and companion ContentType values, return them through generated REST endpoints, and pass them to the generated openFile helper in generators/client/generators/common/templates/src/main/webapp/app/shared/jhipster/data-utils.ts.ejs. The helper uses the returned ContentType as the browser Blob MIME type and opens an object URL, so a normal authenticated user with write access to a Blob-bearing entity can store active HTML or SVG content that may execute under the application origin when a privileged user opens it. Exploitability depends on the generated application's content security policy and target-browser Blob behavior. This issue is fixed in generator-jhipster 9.4.0 and react-jhipster 1.1.0.

Published Oct 8, 2026 · Updated Oct 14, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.3% (30-day exploitation probability)+2
  • Technical severity (high)+6
  • CISA SSVC: exploitation "poc"+5

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.26%
ahead of 17% of scored CVEs · Oct 15, 2026
Affects
Jhipster
Generator-jhipster and 1 more
CVSS base
7.6
High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Proof of concept
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Jhipster Generator-jhipster, Jhipster React-jhipster).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
  4. Search available logs for exploit probes matching the vulnerability class (cross-site scripting), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Jhipster Generator-jhipster version < 9.4.0 Vulnerable CVE Program (cve.org) e CISA ADP
Jhipster React-jhipster version < 1.1.0 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
7.6 CVSS 3.1 High 2.3 4.7 security-advisories@github.com via NIST National Vulnerability Database
7.6 CVSS 3.1 High — — GitHub_M via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N (score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-79 · Cross-site Scripting (XSS)

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.26%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Monitor CSP violation reports and script payloads in reflected parameters.
web/proxy/WAF logsnetwork IDS/IPSapplication logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Source status changed · Undergoing Analysis → Awaiting Analysis
    Oct 14, 2026 · NIST National Vulnerability Database
  • Affected products added · jhipster/generator-jhipster, jhipster/react-jhipster
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • CVSS changed · 7.6
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Undergoing Analysis
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVE published
    Oct 8, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

4 on the record

Elsewhere on this site

Jhipster
every CVE for this vendor
Cross-site scripting
same class
CWE-79
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-107375 JHipster: SQL Injection in the Parameter of JHipster-Generated Reactive (WebFlux + R2DBC) Applicationssort 8d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-107303 is "JHipster: Generated Applications Allow Stored XSS via Unrestricted Blob ContentType Opened as Same-Origin Blob", rated High. It affects Generator-jhipster (Jhipster); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.6 describes technical severity. EPSS 0.26% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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