What is the CVSS score of CVE-2026-8834?

CVE-2026-8834 has a CVSS 3.1 base score of 8.0 (High). CVSS vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Which versions of IBM HTTP Server are affected by CVE-2026-8834?

IBM HTTP Server versions 8.5 and 9.0 contain a buffer overflow vulnerability (CVSS 8.0) that could allow an authenticated administrator to execute arbitrary code on the server.. A patch is available.

How to fix or mitigate CVE-2026-8834?

Within 24 hours: Inventory all IBM HTTP Server 8.5 and 9.0 instances and validate that administrative access is restricted to authorized personnel only. Within 7 days: Obtain and test the vendor patch in a development environment, and schedule a deployment window. Within 30 days: Deploy the patched IBM HTTP Server version to all affected production systems and validate successful upgrades.

IBM HTTP Server CVE-2026-8834

EUVD-2026-31917 HIGH

Heap-based Buffer Overflow (CWE-122)

2026-05-26 ibm

GHSA-34j9-v3rv-pgg8

Denial Of Service Heap Overflow IBM Buffer Overflow Http Server

8.0

CVSS 3.1 · Vendor: ibm

Severity by source

Vendor (ibm) PRIMARY

8.0 HIGH

AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from Vendor (ibm) · only source for this CVE.

CVSS VectorVendor: ibm

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

Attack Vector

Adjacent

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Jun 08, 2026 - 10:10 vuln.today

DescriptionCVE.org

IBM HTTP Server 8.5, and 9.0 contains a buffer overflow vulnerability. A privileged user, authenticated to the Administration Server, could exploit this vulnerability to execute remote code or cause a denial of service.

AnalysisAI

Heap-based buffer overflow in IBM HTTP Server 8.5 and 9.0 allows an attacker already authenticated to the Administration Server to execute arbitrary code or crash the service. The flaw requires adjacent network access and existing low-level privileges, and no public exploit identified at time of analysis despite the high CVSS 8.0 rating. EPSS probability is negligible (0.01%) and SSVC marks exploitation as 'none,' indicating the issue is currently a patch-and-move-on item rather than an emergency.

Technical ContextAI

IBM HTTP Server is IBM's distribution of an Apache HTTP Server derivative, bundled with WebSphere Application Server and managed through a separate Administration Server component that accepts privileged management operations. The vulnerability is classified as CWE-122 (Heap-based Buffer Overflow), meaning a parsing or copy routine in the administrative handling path writes past an allocated heap buffer, enabling memory corruption that can be coerced into either control-flow hijack (RCE) or service termination (DoS). Per CPE cpe:2.3:a:ibm:http_server:*, the affected component is the IHS web server binary itself rather than a third-party module, and the bug is reached through the Administration Server interface rather than the public HTTP listener.

RemediationAI

Apply the vendor patch referenced in IBM Support advisory https://www.ibm.com/support/pages/node/7274065, which provides the corrected interim fix for 8.5.0 (beyond Interim Fix 002) and the patched build for 9.0 - Patch available per vendor advisory. Until the patch is deployed, restrict network reachability of the Administration Server port to a dedicated management VLAN or jump host (this preserves remote administration but breaks any tooling that reaches it from general networks), tighten Administration Server account membership and rotate credentials of any low-trust admins (reduces the PR:L attacker pool at the cost of operator friction), and consider temporarily stopping the Administration Server process where centralized config push is not required (this disables remote admin workflows entirely but eliminates the attack surface). Cross-reference the NVD entry at https://nvd.nist.gov/vuln/detail/CVE-2026-8834 for tracking.