CVE Intelligence
High Cross-site scripting

CVE-2026-108260 — @tinacms/web-components: `tina-markdown` writes rich-text link URLs into `href` without scheme validation, allowing stored XSS

Tina is a headless content management system. Prior to 0.2.1, the tina-markdown element in packages/@tinacms/web-components/src/tina-markdown.js assigns a rich-text node.url value directly to an anchor href without validating the URL scheme. A content author can store a link using a script-capable scheme, and a visitor who clicks the rendered link executes attacker-controlled script in the site's origin. The script can access same-origin application data and, when the visitor is an editor or administrator, may expose credentials stored by the TinaCMS admin on that origin. This issue is fixed in version 0.2.1.

Published Oct 9, 2026 · Updated Oct 13, 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 0.2% (30-day exploitation probability)+1
  • 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
0.21%
ahead of 10% of scored CVEs · Oct 14, 2026
Affects
@tinacms
Tinacms 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 (@tinacms Tinacms, @tinacms Web-components).
  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
@tinacms Tinacms version < 3.14.0 Vulnerable CVE Program (cve.org) e CISA ADP
@tinacms Web-components version < 0.2.1 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 14, 2026 · 2 reading(s) · max 0.21%

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
  • Affected products added · tinacms/tinacms, @tinacms/web-components
    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 · → Received
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVE published
    Oct 9, 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

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

Related CVEs (same products)

  • CVE-2026-108261 TinaCMS admin preview iframe loads an attacker-controlled origin from the URL fragment 6d
  • CVE-2026-108259 Tina: Code injection via unescaped Git branch name in generated client source 6d
  • CVE-2026-63506 Tina: [Broken Access Control] letting any TinaCloud user authorize against any self-hosted site 29d
  • CVE-2026-63123 Tina: Cross-origin `POST /media/upload/*` requests can write arbitrary files into the Tina dev server media root Aug 19, 2026
  • CVE-2026-59992 Tina: Broken Access Control: arbitrary bucket-key write/delete in `next-tinacms-s3` (and sibling production media adapters) Aug 19, 2026
  • CVE-2026-55661 TinaCMS rich-text (slatejson) rendering does not sanitize link/image URLs, allowing stored XSS via dangerous URL schemes Jul 1, 2026

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-2026-108260 is "@tinacms/web-components: `tina-markdown` writes rich-text link URLs into `href` without scheme validation, allowing stored XSS", rated High. It affects Tinacms (@tinacms); 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 0.21% 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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