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TurboDocx html-to-docx EUVDEUVD-2026-101141

| CVE-2026-110718 HIGH
Server-Side Request Forgery (SSRF) (CWE-918)
2026-10-14 VulnCheck GHSA-wh99-p86q-m852
8.2
CVSS 4.0 · Vendor: VulnCheck
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Submit HTML with malicious img src
  2. Delivery
    Bypass loose isValidUrl() check
  3. Exploit
    Server fetches internal/metadata URL
  4. Execution
    Response embedded in DOCX word/media
  5. Impact
    Attacker extracts internal data from document

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V4 - API and Web Service URL allowlisting, SSRF prevention
MITRE ATT&CK

2 techniques across 2 tactics: Initial Access, Credential Access

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Exploitation requires that the application pass attacker-controlled HTML to TurboDocx html-to-docx server-side with image handling active, so that <img src> URLs are fetched during DOCX generation; the attacker-supplied URL must bypass the library's loose isValidUrl() validation and must point at an internal resource (loopback, RFC1918 private ranges, or cloud metadata such as 169.254.169.254) that is actually reachable and responsive from the server. No authentication or user interaction is needed (PR:N/UI:N). Limiting factors raising the bar (reflected in AC:H/AT:P): the attacker needs a valid, live internal target, the fetched response must be embeddable/readable from the returned DOCX word/media folder, and deployments that disable remote image fetching, egress-filter the server, or restrict HTML input are not exploitable.

Impact

This is a genuine but conditional priority rather than a drop-everything emergency. The CVSS 4.0 signals (AV:N, AC:H, AT:P, PR:N, UI:N) describe a remote, unauthenticated SSRF whose exploitation carries higher attack complexity and a specific attack requirement - the attacker must craft input that slips past the loose isValidUrl() check and must have a reachable, responsive internal/metadata target. Confidentiality impact is High (VC:H) while integrity and availability are None, consistent with a read-oriented SSRF that exfiltrates fetched responses into the generated DOCX. Publicly available exploit code exists (VulnCheck advisory plus a HackMD writeup), which raises practical risk and lowers the bar for opportunistic use. No EPSS score and no CISA KEV status were supplied in the input, so there is no evidence of active exploitation and no quantified exploitation probability - the elevated real-world concern here rests on the public POC, not on confirmed in-the-wild activity. Net: the public exploit and unauthenticated network vector justify prompt patching for anyone embedding this library in a server that processes untrusted HTML, but the AC:H/AT:P requirements and confidentiality-only impact mean it is not a wormable, mass-exploitable flaw.

Exploit ScenarioDerived

An attacker submits HTML to a service that uses html-to-docx server-side, embedding an <img> tag whose src points at a loopback, RFC1918, or cloud metadata endpoint (e.g. 169.254.169.254). The server fetches that internal URL and embeds the response bytes into the word/media folder of the returned DOCX, letting the attacker read internal-only content such as cloud instance credentials. A public proof-of-concept and VulnCheck advisory exist, and because PR:N/UI:N no authentication or victim interaction is required, though AC:H/AT:P mean the attacker needs a reachable, responsive internal target.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 0.4% exploitation probability (EPSS)

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AnalysisAIv1 – Oct 14, 2026

TurboDocx html-to-docx through 1.23.1 is vulnerable to server-side request forgery (CWE-918): when an application converts attacker-supplied HTML to DOCX with remote image handling enabled, the library dereferences <img src> URLs server-side, and a loose isValidUrl() check allows loopback, RFC1918 private, and cloud metadata addresses (e.g. 169.254.169.254) to be requested and their responses embedded into the generated document's word/media folder. The flaw is remotely reachable without authentication or user interaction (CVSS:4.0 PR:N/UI:N, 8.2; independent assessment CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N), and publicly available exploit code exists, though there is no confirmed active exploitation (no CISA KEV listing) and no vendor-released patch identified at time of analysis. Real-world risk is conditional rather than universal: the attacker must supply a live, responsive internal target, the fetched response must be readable from the returned DOCX, and deployments that disable remote image fetching, filter outbound traffic, or restrict HTML input are not exploitable.

RemediationAI

No vendor-released patch was identified at time of analysis for CVE-2026-110718, so the primary action is to upgrade html-to-docx beyond 1.23.1 as soon as the maintainer publishes a fixed release (track the project at https://github.com/TurboDocx/html-to-docx and the VulnCheck advisory at https://www.vulncheck.com/advisories/turbodocx-html-to-docx-through-1.23.1-ssrf-via-img-src-remote-image-download; the risk-adding code path is src/utils/image.js#L286). Until then, apply concrete compensating controls. First, disable remote image downloading in the conversion pipeline or strip/neutralize <img> tags from untrusted HTML before conversion - the trade-off is that legitimate remote images will no longer be embedded in generated documents. Second, if remote fetching must stay enabled, force all outbound fetches through an egress proxy or DNS-resolving allowlist that denies loopback (127.0.0.0/8, ::1), RFC1918 ranges (10/8, 172.16/12, 192.168/16), link-local 169.254.0.0/16 (including the 169.254.169.254 metadata endpoint), and other non-public ranges, with re-validation after redirects - this can break integrations that legitimately fetch from internal hosts and requires proxy maintenance. Third, harden the host: enforce IMDSv2 (token-required) on AWS and equivalent protections on other clouds, run the converter in a sandboxed container or dedicated egress-restricted network segment with no metadata route, and drop outbound traffic to metadata and management networks - these add operational overhead but directly remove the high-value targets this SSRF is used to reach. Finally, restrict who can submit HTML to the conversion endpoint, log and alert on outbound requests to internal addresses, and review previously generated DOCX files (word/media folder) for evidence of internal data that may already have been exfiltrated.

Affected VersionsENISA

html-to-docx 0 ≤1.23.1

Affected Packages

euvd html_to_docx no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

TurboDocx html-to-docx is a JavaScript/Node.js library that renders HTML markup into Office Open XML DOCX packages. As part of that rendering it downloads images referenced by HTML <img> tags and writes them into the archive's word/media folder (the remote-image download path referenced in the project source at src/utils/image.js line 286). The SSRF arises because the URL validation performed before fetching (isValidUrl()) is too permissive: it does not reject addresses that resolve to loopback, RFC1918 private ranges, link-local/cloud metadata endpoints, or other non-public resources. An attacker who controls the HTML passed into the conversion therefore controls the server's outbound request target, and because the fetched bytes are placed into the DOCX, the attacker can read the response body back out of the generated document - turning the SSRF into a data-exfiltration primitive against internal-only HTTP services and instance metadata endpoints. The root-cause class, CWE-918, is a classic validation-of-target-address failure: hostname/IP allow/deny logic must be applied after DNS resolution (and re-checked on redirects) to be effective, which the loose check does not do. The affected component is tracked as CPE cpe:2.3:a:turbodocx:html-to-docx:*:*:*:*:*:*:*:*.

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Severity by source

Vendor (VulnCheck) PRIMARY 8.2 HIGH
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
vuln.today AI 5.9 MEDIUM

Remote unauthenticated (AV:N/PR:N/UI:N) but AC:H because the attacker must evade isValidUrl() and hit a live internal target; confidentiality-only (C:H, I/A:N) read SSRF.

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
4.0 AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

Attack Vector
Network
Attack Complexity
High
Attack Requirements
Present
Privileges Required
None
User Interaction
None
Vulnerable system: Confidentiality
High
Vulnerable system: Integrity
None
Vulnerable system: Availability
None
Subsequent system: Confidentiality
None
Subsequent system: Integrity
None
Subsequent system: Availability
None

DescriptionCVE.org

TurboDocx html-to-docx through 1.23.1 contains a server-side request forgery vulnerability that allows attackers supplying HTML to make the server fetch internal URLs via img src attributes. Attackers can reference loopback, private, or cloud metadata addresses that bypass the loose isValidUrl() check, and read responses embedded in the generated DOCX word/media folder.

Executive ViewAI

Why It Matters

TurboDocx html-to-docx, through version 1.23.1, can be induced to fetch internal network resources - including cloud metadata endpoints such as 169.254.169.254 - and embed the responses directly into documents it generates, and no vendor patch is currently available. The flaw is remotely reachable without authentication or user interaction, so any service that converts untrusted HTML to DOCX with remote image handling enabled becomes a potential exfiltration channel for internal data through a routine document-generation feature. Leadership should care because captured cloud metadata and internal service responses can enable broader cloud account compromise and lateral movement, while remediation today depends on configuration and network controls rather than a vendor fix.

Business Impact: High
Compensating Controls

No vendor-released patch identified at time of analysis. Interim mitigations: disable remote image handling in TurboDocx html-to-docx (or keep it at 1.23.1 with remote fetching off), enforce outbound egress allowlists that block loopback, RFC1918, and link-local/169.254.169.254 metadata destinations, require authentication and strict input validation on all HTML-to-DOCX conversion endpoints, enable cloud metadata protections such as IMDSv2, and monitor logs for server-side requests to internal or metadata addresses.

Threat Intelligence Overview

EPSS Score
0.4%
Top 63% exploitable
Prevalence
Low
niche npm HTML-to-DOCX conversion library, developer-integrated not broadly deployed
Exploit
POC
Public exploit code exists
Data Quality
6 sources
Confidence: High

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC Yes
EPSS 0.4%
Patch available No
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
Poc
System Exposure· derived
Open
Automatable
No
Human Impact
High
Technical Impact
Partial

Priority Score

61
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +41
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Server-Side Request Forgery exploits applications that fetch remote resources based on user-supplied URLs.

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