xml-crypto Vulnerable to XML Signature Verification Bypass via DigestValue Comment
Not confirmed exploited. 1 of 9 rule sources name it; Vercel blocks by default.
What it is
xml-crypto is an XML digital signature and encryption library for Node.js. An attacker may be able to exploit a vulnerability in versions prior to 6.0.1, 3.2.1, and 2.1.6 to bypass authentication or authorization mechanisms in systems that rely on xml-crypto for verifying signed XML documents. The vulnerability allows an attacker to modify a valid signed XML message in a way that still passes signature verification checks. For example, it could be used to alter critical identity or access control attributes, enabling an attacker to escalate privileges or impersonate another user. Users of versions 6.0.0 and prior should upgrade to version 6.0.1 to receive a fix. Those who are still using v2.x or v3.x should upgrade to patched versions 2.1.6 or 3.2.1, respectively.
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The risk
It is reachable over the network without credentials or any user interaction (CVSS 9.3). Exploitation in the wild is not established by CISA KEV.
Who is affected
Teams running node-saml xml-crypto (>= 4.0.0, < 6.0.1; >= 3.0.0, < 3.2.1; < 2.1.6). Prioritise internet-facing instances.
Next steps
- Apply the vendor's fix; the advisory lists the affected and fixed versions.
- Keep a WAF rule in place while you patch: Vercel blocks it by default. A WAF rule reduces exposure; it does not replace the patch. Edge coverage
- Check which WAF sits in front of your site and whether it covers this CVE. Check your domain
Edge coverage
Claimed by vendorsAttack traffic on Cloudflare
Cloudflare Radar- Broken Authentication14% of mitigated layer 7 attacks, 7 days
- Rules for named CVEs5.6% of mitigated layer 7 attacks, 7 days
Radar groups Cloudflare's WAF managed rules by category; it does not publish counts per CVE. These shares show how much attack traffic targets this kind of flaw across Cloudflare's network (28-day trend). They are not compromised systems, and seeing few attempts on Cloudflare does not prove an absence elsewhere. Radar data as of 2026-11-04. Radar ↗
Check your exposure with an agent
Read-onlyCopy this into an agent with access to your infrastructure. It asks for an evidence-based, read-only assessment: affected systems, exposure, compensating controls and what is still unknown. It does not scan or change anything by itself.
Prompt
Assess whether the infrastructure available to you is affected by CVE-2025-29775 (xml-crypto Vulnerable to XML Signature Verification Bypass via DigestValue Comment). Perform a read-only assessment within your authorized access. Do not send exploit traffic, scan third-party systems, change configuration or restart services. 1. Verify the CVE record at https://www.cve.org/CVERecord?id=CVE-2025-29775 and the vendor advisory. Establish affected and fixed versions, including vendor backports. The record lists: node-saml xml-crypto: affected >= 4.0.0, < 6.0.1; >= 3.0.0, < 3.2.1; < 2.1.6. Cite sources and retrieval dates; flag anything you cannot verify. 2. Inventory deployments of node-saml xml-crypto: asset, environment, owner where known, installed version or build, and how you confirmed it (package metadata, a version endpoint, image tags). An image tag alone does not prove the running version. 3. Identify which deployments are reachable from the internet or untrusted networks, and through which paths (direct origin, load balancer, CDN or WAF). 4. Assess compensating controls separately from patch status. Current edge WAF coverage for this CVE: Vercel: rule blocks by default. Live data: https://cve.vigilbase.com/api/v1/cves/CVE-2025-29775. Check whether the rule is enabled and in block mode on each path, and whether any path bypasses the WAF. A WAF rule is not a patch. 5. Check logs on exposed instances for requests matching the public exploit, if your access allows. Return a short summary and a table: asset | version/build | assessment (affected, fixed, not applicable, unknown) | exposure | compensating control | evidence | next action. List what you could not assess and the access needed to resolve it. Do not infer absence of compromise from patch status or a lack of alerts. Remediation guidance: Apply the vendor's fix; the advisory lists the affected and fixed versions. Keep a WAF rule in place while you patch: Vercel blocks it by default. A WAF rule reduces exposure; it does not replace the patch. More: https://cve.vigilbase.com/cve/CVE-2025-29775
Sources
Cited- CVE record
CVSS 4.0 9.3 (critical). Weakness: CWE-347.
- Exploit evidence
No public exploit code found in Exploit-DB, Metasploit, nuclei-templates or GitHub. That does not mean none exists.
- CISA KEV
Not in the KEV catalog (catalog 2026.11.03, checked 2026-11-04). Absence from KEV is not evidence that it cannot be exploited.
- WAF vendor statements
Vercel names it in a changelog. Quotes and dates below.
Ask Vigil
AI · answers from this pageSeverity, decoded
CVSS 4.0Exploitable over the network, with no privileges and no user interaction, leading to full loss of confidentiality, integrity and availability.
How the score is built
- Attack vectorAn attacker can reach it over the internet; no access to your network needed.Network
- Attack complexityNo built-in defences have to be bypassed; the attack works reliably.Low
- Attack requirementsThe attack works without any special deployment or timing conditions.None
- Privileges requiredNo account or login is needed.None
- User interactionNo one has to click or open anything; the attack works on its own.None
- Confidentiality impact (vulnerable system)An attacker can read all data the affected component holds, or the most sensitive parts of it.High
- Integrity impact (vulnerable system)An attacker can change any data or files the affected component protects.High
- Availability impact (vulnerable system)An attacker can take the component down completely or keep it from serving anyone.High
- Confidentiality impact (other systems)Other systems' data is not exposed.None
- Integrity impact (other systems)Other systems' data cannot be changed.None
- Availability impact (other systems)Other systems keep working normally.None
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NPublic exploit code or a detailed write-up exists, but CISA has not seen attacks.
Attackers can script the attack end to end and hit many targets at once.
A successful attack gives full control over the affected software or all of its data.
Public exploits
None foundNo exploit in Exploit-DB or Metasploit, and no scanner template. That lowers, but doesn't remove, the chance of mass exploitation.
Timeline
- 2025-03-14CVE publishedCVE List
- 2025-03-18Vercel ships a ruleVercel Firewall protects against the SAMLStorm vulnerability
Vendor statements
QuotedCloudflareWAF Managed Rules
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. Each row gives the rule ID and its default action. The feed starts in January 2025, so older rules are missing.
AWSAWS WAF Managed Rules
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. AWS often describes a vulnerability without naming its CVE (for example "Log4j"). We count only entries that name the CVE, so AWS coverage is understated.
Microsoft AzureFront Door and Application Gateway WAF (DRS)
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. The rule tables name CVEs but carry no dates, so Azure is left out of every time-to-rule figure.
Google CloudCloud Armor preconfigured WAF rules
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. Google names few CVEs: the release notes start in May 2024 and the rules reference lists CVEs without dates. Its cve-canary rules are opt-in.
FastlyNext-Gen WAF virtual patches
The CVE predates the oldest entry in this vendor's public feed, so a rule may exist that we cannot see.
VercelVercel WAF (platform rules)
First rule 2025-03-18, 4 days after the CVE was published.
We have deployed a proactive security update to the Vercel Firewall , protecting against a recently disclosed vulnerability in the xml-crypto package, dubbed SAMLStorm ( CVE-2025-29774 and CVE-2025-29775 ).
F5Attack signatures (Distributed Cloud WAF)
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. Each signature lists the CVEs it references, with its id and date. F5 does not state a default action; signatures enforce once staging ends in your policy.
AkamaiApp & API Protector (Adaptive Security Engine)
This vendor publishes no machine-readable rule changelog we can check.
OWASP CRSCore Rule Set (open source, used inside many WAFs)
We found no public statement from this vendor naming this CVE. That is not proof of no protection: generic rules may still catch it. CRS rarely names CVEs: it relies on generic detections. Our own lab measures what it actually blocks.
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