CVE-2026-113658Published

ApostropheCMS: Unauthenticated CSV import requests leave rejected uploads in the system temporary directory

Collected exploitation and prediction evidence

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

cve-program · CVE-2026-113658

Published

ApostropheCMS is an open-source Node.js content management system. Prior to 4.33.0, the unauthenticated Rich Text CSV conversion route writes a multipart upload to the system temporary directory before checking its extension and does not remove the staged file when that validation rejects it. Repeated large rejected uploads, using the normal public CSRF cookie, can persistently consume temporary-disk capacity and may disrupt ApostropheCMS and other services that depend on the same partition. This issue is fixed in version 4.33.0.

Source published: 20 Oct 2026 16:56:01 UTC
Source modified: 23 Oct 2026 01:55:01 UTC
Observed here: 23 Oct 2026 16:01:20 UTC
Source terms: CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

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CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

euvd · EUVD-2026-105188

Published

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: Oct 20, 2026, 4:56:01 PM

dateUpdated: Oct 23, 2026, 1:55:01 AM

Source published: Oct 20, 2026, 4:56:01 PM (timezone not stated)
Source modified: Oct 23, 2026, 1:55:01 AM (timezone not stated)
Observed here: 7 Nov 2026 04:34:20 UTC
Source terms: ENISA EUVD · source terms and attribution apply

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EUVD CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd · CVE-2026-113658

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Deferred

Weakness classifications: CWE-400 · CWE-459 · CWE-770

Original publisher date fields

published: 2026-10-20T17:17:36.917

lastModified: 2026-10-23T02:16:56.200

Source published: 20 Oct 2026 17:17:36 UTC
Source modified: 23 Oct 2026 02:16:56 UTC
Observed here: 25 Oct 2026 05:17:18 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

osv · GHSA-qhcq-9pm2-c9w9

Published

### Summary A rejected upload can remain in the operating system temporary directory. Multer writes the file before its extension is checked, and the rejection path does not remove that temporary file. An unauthenticated requester can repeat this with large files and steadily consume temporary disk space. ### Details The endpoint is: ```text POST /api/v1/@apostrophecms/rich-text-widget/generate-csv-table ``` In `packages/apostrophe/modules/@apostrophecms/rich-text-widget/lib/apiRoutes.js`, Multer first writes the upload to `os.tmpdir()`. The handler then rejects filenames whose extension is not `csv`, but there is no cleanup of the Multer file on this error path. The route does not require an authenticated user. A normal CSRF cookie is sufficient. During testing, the request returned HTTP 400 with `Only csv files are supported`, while the complete uploaded content remained in a randomly named file in the configured temporary directory after the response. ### Relationship to prior public work I reviewed [PR #5013](https://github.com/apostrophecms/apostrophe/pull/5013), which migrated the Rich Text CSV upload path from `connect-multiparty` to Multer. This report concerns cleanup after that migration: the rejected Multer file remains on disk, a behavior not described in the PR or its review discussion. ### POC Create a small test file. A larger file can be used to demonstrate disk growth, but 1 MiB is enough for a safe local reproduction: ```bash dd if=/dev/zero of=rejected.txt bs=1M count=1 ``` Obtain the normal site cookies and send the rejected upload: ```bash curl -c cookies.txt 'http://127.0.0.1:3000/' > /dev/null curl -i -b cookies.txt \ -F '[email protected];filename=rejected.txt;type=text/plain' \ 'http://127.0.0.1:3000/api/v1/@apostrophecms/rich-text-widget/generate-csv-table' ``` The response is HTTP 400. Compare the contents of the system temporary directory before and after the request: ```bash ls -lt /tmp ``` A new randomly named file remains present and contains the uploaded bytes. No login is required. Repeating the multipart request creates additional persistent temporary files. ### Impact A remote unauthenticated attacker can fill the partition used by the operating system temporary directory. Once that partition is exhausted, Apostrophe and unrelated services on the same host may fail to upload files, create temporary data, or continue operating normally. The attack requires only repeated HTTP requests and the stored files remain after each rejected response.

Source published: 20 Oct 2026 18:10:32 UTC
Source modified: 20 Oct 2026 18:15:04 UTC
Observed here: 24 Oct 2026 13:17:17 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Publisher rating · HIGH