CVE-2026-33521 BUG-000186514 - ArcGIS Server has a security vulnerability.
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-33521?
CVE-2026-33521 is a high-severity vulnerability in Esri ArcGIS Server, published on 26 Oct 2026.
Official description
There is s denial of service vulnerability in Esri ArcGIS Server versions 12.0 and prior that may allow a remote, unauthenticated attacker to supply crafted requests that may, under exceptional circumstances, consume all available worker threads and deny service to users. A patch is provided for ArcGIS Server software in General Availability and Extended support status, which includes versions 12.0, 11.5, 11.3, and 11.1. Other versions are in mature or retired status, which are not patch eligible. Users working with unlisted versions are advised to upgrade and apply the patch.
Weakness: CWE-400
Which versions are affected by CVE-2026-33521?
How do I fix CVE-2026-33521?
No fix has been published for CVE-2026-33521 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-33521 being exploited?
There is no known exploitation of CVE-2026-33521 in the wild and no public exploit code.
Sources
Also known as GHSA-wc5q-3mff-vvxv.