CVE-2021-29447

Wordpress is an open source CMS. A user with the ability to upload files (like an Author) can exploit an XML parsing issue in the Media Library leading to XXE attacks. This requires WordPress installation to be using PHP 8. Access to internal files is possible in a successful XXE attack. This has been patched in WordPress version 5.7.1, along with the older affected versions via a minor release. We strongly recommend you keep auto-updates enabled.

CVSS: 7.1Highscored by the publisher (CNA)
Exploited in the wild: Not knownPublic exploit code; not in CISA KEV
EPSS: 85.7%chance of exploitation in the next 30 daystop 0.3% of scored CVEsFIRST score of 11 Nov 2026
Fix: Patch availablesee the advisories in the references
Published: 15 Apr 2021analysed here 12 Nov 2026

Summary

Triage

Attack surface: Server-side
Exploitable: At runtime
Attack vector: network
Weakness: CWE-611 XML External Entity (XXE)
Can a WAF block it?: Partly. See why

The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.

Affected products

Product	Affected versions	Vendor says fixed in
WordPress wordpress-develop	>= 5.6.0 and < 5.7.1Vendor says fixed in: not stated	Not stated by the vendor

As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.

Products named in our analysis

wordpress:wordpress
debian:debian_linux

Fix and mitigation

WAF and other mitigations

Can a WAF block it? Partly. XXE needs a DOCTYPE in the XML body. WAF rules block that pattern, but XML wrapped in JSON, SOAP or file uploads can get past them.

Also consider: disable DTDs in parser

Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.

Remediation steps (AI-written)

Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.

Exploitation evidence

CISA KEV catalog: Not listed as of our last sync.
Public exploit code: Yes: 1 on Exploit-DB · 24 GitHub proofs of concept

Exploit-DB

WordPress 5.7 - 'Media Library' XML External Entity Injection (XXE) (Authenticated)webapps, 20 Sept 2021

GitHub proofs of concept

motikan2010/CVE-2021-2944744 stars
mega8bit/exploit_cve-2021-294477 stars
0xRar/CVE-2021-29447-PoC6 stars
Vulnmachines/wordpress_cve-2021-294474 stars

and 20 more repositories

Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.

Timeline

15 Apr 2021Published
16 Apr 2021First public exploit or proof of conceptsame day later
3 Aug 2024CVE record last updated1,206 days (about 3 years) later
12 Nov 2026Analysed by vulneraibility.com831 days (about 2 years) later

CVSS vector

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

Metric	Value	What it means
Attack vector	NetworkReachable over the internet or any routable network.	Reachable over the internet or any routable network.
Attack complexity	LowRepeatable attack, no special conditions.	Repeatable attack, no special conditions.
Privileges required	LowThe attacker needs basic user privileges.	The attacker needs basic user privileges.
User interaction	NoneNo victim action needed.	No victim action needed.
Scope	UnchangedImpact stays within the vulnerable component.	Impact stays within the vulnerable component.
Confidentiality	HighTotal data disclosure possible.	Total data disclosure possible.
Integrity	LowLimited modification possible.	Limited modification possible.
Availability	NoneThe service stays up.	The service stays up.

Common questions

Is CVE-2021-29447 being exploited?

Not confirmed. CVE-2021-29447 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 86% probability of exploitation in the next 30 days.

How severe is CVE-2021-29447?

CVE-2021-29447 is rated High with a CVSS score of 7.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2021-29447?

Yes. A fix has been recorded for CVE-2021-29447. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2021-29447 affect?

CVE-2021-29447 affects wordpress:wordpress, debian:debian_linux. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

References

NVD CVE.org CVE Details Source

7 references in the CVE record, grouped by the tags the record gives them.

Advisories (1)

debian.org /security/2021/dsa-4896

Where the data on this page comes from

CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
NVD: CVSS and CPE data
FIRST EPSS: exploit probability and percentile
Exploit-DB: published exploits
PoC-in-GitHub: GitHub repositories that claim a proof of concept

Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.

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