Read the docs
TI-2026-80539 Aliases CVE-2026-33521GHSA-wc5q-3mff-vvxv

Denial of service in Esri ArcGIS Server via crafted requests

Priority LOW 39CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-400.

Summary

Esri ArcGIS Server from 11.1 before 12.0 contains a denial of service flaw classified as uncontrolled resource consumption (CWE-400). A remote, unauthenticated attacker can send crafted requests that, under exceptional circumstances, consume all available worker threads and deny service to users.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00448 39th percentileScored 2026-11-07
Fix Fixed ArcGIS Server (Esri): 12.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
EsriArcGIS Server11.1 to before 12.012.0Patch availableCNA
  • ArcGIS Server VendorEsri Affected 11.1 to before 12.0 Fixed in 12.0 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:esri:arcgis_server:*:*:*:*:*:*:*:*——Esri
  • cpe:2.3:a:esri:arcgis_server:*:*:*:*:*:*:*:* Versions — — ·Esri

Remediation

Esri ArcGIS Server 12.0 fixes the flaw. The sources provide a patch for ArcGIS Server 12.0, 11.5, 11.3 and 11.1 in General Availability and Extended support. Other versions are in mature or retired status and are not patch eligible, so users on unlisted versions should upgrade.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA ArcGIS Server (Esri) Fixed in 12.0

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Esri ArcGIS Server 12.0

    2 records Highest priority Priority LOW 2 LOW

    Other records, highest priority first

    • TI-2026-80540 Improper authorization in Esri ArcGIS Server allows metadata updatesPriority LOW 30
    Show all 2 records →

Timeline

  1. 2026-10-26 Threatist record created from CVE-2026-33521
  2. 2026-10-26 CISA SSVC decision points changed
  3. 2026-10-26 Priority changed: MEDIUM → LOW
  4. 2026-10-27 Alias added: GHSA-wc5q-3mff-vvxv

References

Other 1

  • TI-2024-16901 Portal for ArcGIS has a directory traversal vulnerability. CVSS 3.1CRITICAL 9.9
  • TI-2012-01450 ESRI ArcMap 9 and ArcGIS 10.0.2.3200 and earlier does not properly prompt users before… CVSS 2.0HIGH 9.3
  • TI-2007-01695 Buffer overflow in the ArcSDE service (giomgr) in Environmental Systems Research… CVSS 2.0HIGH 10.0
  • TI-2026-08070 Directory Traversal in ArcGIS Server CVSS 3.1CRITICAL 9.8
  • TI-2026-11074 Missing authentication in Esri Portal for ArcGIS CVSS 3.1CRITICAL 9.8
  • TI-2025-35724 BUG-000179884 - There is a security vulnerability in ArcGIS Server Feature Services. CVSS 3.1CRITICAL 10.0
See all 194 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences