CVE-2026-34088: Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki. T

Routine

HIGH 7.5REMOTEUPGRADE

CVE-2026-34088 is a high-severity flaw (CVSS 7.5) affecting mediawiki. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki. This issue affects MediaWiki: from * before 1.43.7, 1.44.4, 1.45.2.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 79%)
CISA exploited list	No
Weakness	CWE-200
Published	2026-05-11
Last modified	2026-10-26

Publisher (CNA): wikimedia-foundation · Vendor: mediawiki

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-11 16:17 UTCPublished CVE record published
2026-10-26 18:10 UTCUpdated Record last modified

mediawiki mediawiki UPGRADE

Affected: < 1.43.7 · >= 1.44.0 and < 1.44.4 · >= 1.45.0 and < 1.45.2

Fixed in: 1.43.7, 1.44.4, 1.45.2

Safe to downgrade to: a release before 1.44.0

1. Check installed version

apt-cache policy mediawiki || rpm -q mediawiki || mediawiki --version

2. UPGRADE to 1.43.7 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mediawiki

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mediawiki

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 1.44.0 (Debian / Ubuntu)

apt-cache madison mediawiki sudo apt install mediawiki=<VERSION_BEFORE_1.44.0> sudo apt-mark hold mediawiki

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

dnf --showduplicates list mediawiki sudo dnf downgrade mediawiki-<VERSION_BEFORE_1.44.0> sudo dnf versionlock add mediawiki

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-2026-34088?

mediawiki: upgrade to 1.43.7, 1.44.4, 1.45.2. Exact commands for each OS are on this page.

Is CVE-2026-34088 being exploited?

CVE-2026-34088 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-2026-34088 affect?

CVE-2026-34088 affects mediawiki. Severity is high (CVSS 7.5). Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki. This issue affects MediaWiki: from * before 1.43.7, 1.44.4, 1.45.2.

How urgent is CVE-2026-34088?

Priority 37/100. High severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-34091 HIGH 7.5 UPGRADE Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki. T
CVE-2026-34087 HIGH 7.5 UPGRADE Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation OATHAuth. Th
CVE-2026-34093 MEDIUM 5.3 UPGRADE Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki.
CVE-2026-34095 MEDIUM 6.1 UPGRADE Vulnerability in Wikimedia Foundation MediaWiki. This vulnerability is associated with program files include
CVE-2026-34094 LOW 3.8 UPGRADE Vulnerability in Wikimedia Foundation MediaWiki. This vulnerability is associated with program files include

References

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