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Response snapshot Nov 5, 2026, 23:11 UTC

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VulnerabilityCVE-2026-102615

HeyForm is an open-source form builder.

HeyForm is an open-source form builder. Prior to 3.0.1, /api/upload accepts a file according to the client-controlled multipart file.mimetype while retaining an HTML filename, and static/upload serves the resulting file as text/html with contentSecurityPolicy: false.

At a glance

Exploited
Not known
Severity
7.6 High (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-102615 (opens a new tab)

What happened

HeyForm is an open-source form builder. Prior to 3.0.1, /api/upload accepts a file according to the client-controlled multipart file.mimetype while retaining an HTML filename, and static/upload serves the resulting file as text/html with contentSecurityPolicy: false. An ordinary user can therefore upload active HTML that executes on the HeyForm origin when a victim opens its returned URL.

The same-origin script can access /graphql with the victim's session and read or modify data available to that account. The code also permits upload requests tied to an active public form through formId, openToken, and a fieldId belonging to a file or signature question, although the advisory did not fully verify that unauthenticated path end to end. This issue is fixed in version 3.0.1.

Scores and how they were measured

CVSS base severity

7.6

Version 3.1As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Sources

  1. Primary source

    NVD CVE-2026-102615 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  4. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, November 5). HeyForm is an open-source form builder. (CVE-2026-102615). https://kevwire.com/record/CVE-2026-102615

MLA

"HeyForm is an open-source form builder. (CVE-2026-102615)." KEVWire, 5 Nov. 2026, kevwire.com/record/CVE-2026-102615.

Chicago

KEVWire. "HeyForm is an open-source form builder. (CVE-2026-102615)." Last modified November 5, 2026. https://kevwire.com/record/CVE-2026-102615.

Evidence summary (plain text)

HeyForm is an open-source form builder. (Nov 5, 2026).
HeyForm is an open-source form builder. Prior to 3.0.1, /api/upload accepts a file according to the client-controlled multipart file.mimetype while retaining an HTML filename, and static/upload serves the resulting file as text/html with contentSecurityPolicy: false. An ordinary user can therefore upload active HTML that executes on the HeyForm origin when a victim opens its returned URL. The same-origin script can access /graphql with the victim's session and read or modify data available to that account.
CVSS 7.6 (version 3.1; evidence as of Nov 5, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-102615).
Sources:
NVD CVE-2026-102615: https://nvd.nist.gov/vuln/detail/CVE-2026-102615
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-05T16:06:14.984Z&lastModEndDate=2026-11-05T17:35:56.143Z&resultsPerPage=500&startIndex=500
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-05T15:36:26.668Z&lastModEndDate=2026-11-05T17:05:56.758Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-11-05T15:01:02.006Z&lastModEndDate=2026-11-05T16:35:57.513Z&resultsPerPage=500&startIndex=500
Record ID: CVE-2026-102615.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Nov 5, 2026, 17:35 UTC. Ingestion is not an independent editorial investigation.

NVD status: Deferred. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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