CVE-2026-63334 — draw.io: SSRF via DNS rebinding in ProxyServlet bypasses private IP blocklist
draw.io is a configurable diagramming and whiteboarding application. Prior to version 30.2.7, deployments with ENABLE_DRAWIO_PROXY=1 are vulnerable to server-side request forgery because src/main/java/com/mxgraph/online/Utils.java performs the private-address check in Utils.sanitizeUrl() using one DNS resolution, while src/main/java/com/mxgraph/online/ProxyServlet.java later calls URL.openConnection() and performs a second resolution. An attacker-controlled hostname can resolve to a public address during validation and then to a private, link-local, or cloud metadata address when the connection is opened. Successful exploitation can return cloud instance metadata or responses from internal HTTP services through the proxy. This issue is fixed in version 30.2.7.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.3% (30-day exploitation probability)+3
- Technical severity (medium)+3
- 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.
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.
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.
- Identify exposed assets running the affected vendor/product/version combinations (Jgraph Drawio).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (logic error), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 6.8 | CVSS 3.1 | Medium | 2.2 | 4.0 | security-advisories@github.com via NIST National Vulnerability Database |
| 6.8 | CVSS 3.1 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
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).
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · jgraph/drawio
- SSVC assessment updated
- Record published
- CVSS changed · 6.8
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
3 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-76898 draw.io: Unauthenticated SSRF via IPv6 ULA blocklist bypass in /embed2.js 24d
- Medium CVE-2026-63373 draw.io: OAuth CSRF via missing state validation on self-hosted deployments allows session token injection 24d
- Low CVE-2026-63416 draw.io: Path traversal in ExportProxyServlet allows access to arbitrary backend endpoints 24d
- Medium CVE-2026-58504 draw.io: Stored XSS on file open via editable=0 sibling cell — patch bypass of CVE-2026-46642 24d
- Medium CVE-2026-46642 draw.io: XSS via crafted cell label when opening a .drawio file Jun 10, 2026
- Low CVE-2026-42195 Unvalidated gitlab URL parameter redirects OAuth authorize step to attacker-controlled host May 8, 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-2026-63334 is "draw.io: SSRF via DNS rebinding in ProxyServlet bypasses private IP blocklist", rated Medium. It affects Drawio (Jgraph); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.8 describes technical severity. EPSS 0.32% 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.
Comments
Moderated technical discussion. Read the community guidelines.
No comments yet.
Sign in or create an account to comment and suggest corrections.