CVE-2026-71428: unstructured: Server-Side Request Forgery in the URL-based partitioning

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.4%, percentile 37: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 37% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes unstructured (PyPI) >= 0.4.7, < 0.24.0, fixed in 0.24.0. Check your lockfile, including transitive dependencies.

What it is

The unstructured library provides open-source components for ingesting and pre-processing images and text documents, such as PDFs, HTML, Word docs, and many more. From 0.4.7 until 0.24.0, the url argument of partition, partitionhtml, and partitionmd is fetched without host validation in unstructured/partition/auto.py, unstructured/partition/html/partition.py, and unstructured/partition/md.py. An attacker who controls that URL can make a server-side ingestion service request loopback addresses, internal HTTP services, or cloud metadata endpoints through direct targets, redirects, or DNS rebinding. The response body is returned as Element text, allowing internal response disclosure, and side-effecting GET endpoints may also be triggered. This issue is fixed in version 0.24.0.

From the GitHub advisory

Summary

Server-Side Request Forgery in unstructured. The url= argument of partition(), partitionhtml(), and partitionmd() is fetched via requests.get() with no host validation. The response body is returned as Element text, so this is a full-read SSRF — attackers reach loopback admin APIs, internal HTTP services, and cloud metadata endpoints, and read the response.

unstructured is the de facto URL ingestion layer for LangChain UnstructuredURLLoader, LlamaIndex UnstructuredReader, Chainlit, and many agent frameworks — secure defaults must live in the library, not in every downstream caller.

Details

Three sinks, all in unstructured == 0.22.26 (verified on main at 199f255):

Weakness type: CWE-601, CWE-918.

Product: unstructured (PyPI) · Assigned by: GitHub_M · Published: 2026-08-20

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: none (no login)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable yes, technical impact partial.
• FIRST EPSS (model of 2026-10-21): 0.44% probability of exploitation activity in the next 30 days; percentile 37.

Timeline

• 2026-08-20 — CVE record published by GitHub_M
• 2026-08-25 — CVE record last updated
• 2026-09-03 — GitHub-reviewed advisory GHSA-4mvj-m6j5-pmf7 published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-4mvj-m6j5-pmf7 github.com
2. CVE.org record CVE-2026-71428 cve.org
3. NVD entry CVE-2026-71428 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com
4. github.com github.com

Critical PyPI advisories · Today’s Security Digest