GHSA-WR76-29CR-67W8
Vulnerability from github – Published: 2026-06-01 09:31 – Updated: 2026-07-09 21:03A bug in Apache Airflow's XCom PATCH endpoint PATCH /api/v2/xcomEntries/{key} allowed an authenticated UI/API user with XCom write permission on a Dag to set XCom entries under reserved key names (e.g. return_value) that the matching POST endpoint already validated against FORBIDDEN_XCOM_KEYS. The endpoint also accepted serialized payload shapes the triggerer's deserializer treats as code; combined, this allowed RCE on the triggerer when the affected task next deferred. Affects deployments where untrusted users have XCom write permission on Dags that defer to the triggerer. This is a fix-bypass of CVE-2026-33858: PR #64148 added the FORBIDDEN_XCOM_KEYS validator only on the POST/set path; the PATCH path was not covered. Users who already upgraded for CVE-2026-33858 should additionally upgrade to apache-airflow 3.2.2 or later to cover the PATCH-path bypass.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "apache-airflow"
},
"ranges": [
{
"events": [
{
"introduced": "3.2.0"
},
{
"fixed": "3.2.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-42359"
],
"database_specific": {
"cwe_ids": [
"CWE-502"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-09T21:03:20Z",
"nvd_published_at": "2026-06-01T09:16:18Z",
"severity": "HIGH"
},
"details": "A bug in Apache Airflow\u0027s XCom PATCH endpoint `PATCH /api/v2/xcomEntries/{key}` allowed an authenticated UI/API user with XCom write permission on a Dag to set XCom entries under reserved key names (e.g. `return_value`) that the matching POST endpoint already validated against `FORBIDDEN_XCOM_KEYS`. The endpoint also accepted serialized payload shapes the triggerer\u0027s deserializer treats as code; combined, this allowed RCE on the triggerer when the affected task next deferred. Affects deployments where untrusted users have XCom write permission on Dags that defer to the triggerer. This is a fix-bypass of CVE-2026-33858: PR #64148 added the `FORBIDDEN_XCOM_KEYS` validator only on the POST/set path; the PATCH path was not covered. Users who already upgraded for CVE-2026-33858 should additionally upgrade to `apache-airflow` 3.2.2 or later to cover the PATCH-path bypass.",
"id": "GHSA-wr76-29cr-67w8",
"modified": "2026-07-09T21:03:20Z",
"published": "2026-06-01T09:31:14Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42359"
},
{
"type": "WEB",
"url": "https://github.com/apache/airflow/pull/65915"
},
{
"type": "PACKAGE",
"url": "https://github.com/apache/airflow"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/apache-airflow/PYSEC-2026-185.yaml"
},
{
"type": "WEB",
"url": "https://lists.apache.org/thread/g8dqykpf1p90tysq8tln4qtkqwb1038s"
},
{
"type": "WEB",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-33858"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
],
"summary": "Apache Airflow has a Deserialization of Untrusted Data vulnerability"
}
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Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
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- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
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- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
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