CVE-2026-8834: IBM HTTP Server 8.5, and 9.0 contains a buffer overflow vulnerability

Routine

HIGH 8.0UPGRADE

CVE-2026-8834 is a high-severity flaw (CVSS 8.0) affecting http server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.0 (High)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 82%)
CISA exploited list	No
Weakness	CWE-122
Published	2026-05-26
Last modified	2026-07-23

Publisher (CNA): IBM Corporation · Vendor: ibm

Last updated 2026-07-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-26 18:16 UTCPublished CVE record published
2026-07-23 11:10 UTCUpdated Record last modified

ibm http server UPGRADE

Affected: >= 8.5.0.0 and < 8.5.5.30 · >= 9.0.0.0 and < 9.0.5.29

Fixed in: 8.5.5.30, 9.0.5.29

Safe to downgrade to: a release before 8.5.0.0

1. Check installed version

apt-cache policy http-server || rpm -q http-server || http-server --version

2. UPGRADE to 8.5.5.30 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade http-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade http-server

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 8.5.0.0 (Debian / Ubuntu)

apt-cache madison http-server sudo apt install http-server=<VERSION_BEFORE_8.5.0.0> sudo apt-mark hold http-server

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list http-server sudo dnf downgrade http-server-<VERSION_BEFORE_8.5.0.0> sudo dnf versionlock add http-server

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-8834?

http server: upgrade to 8.5.5.30, 9.0.5.29. Exact commands for each OS are on this page.

Is CVE-2026-8834 being exploited?

CVE-2026-8834 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-8834 affect?

CVE-2026-8834 affects http server. Severity is high (CVSS 8.0). 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.

How urgent is CVE-2026-8834?

Priority 32/100. High severity

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References

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