CVE-2026-73478: Incorrect Authorization vulnerability in Drupal Diff allows Forceful Browsing

Routine

MEDIUM 5.3REMOTEUPGRADE

CVE-2026-73478 is a medium-severity flaw (CVSS 5.3) affecting diff. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Incorrect Authorization vulnerability in Drupal Diff allows Forceful Browsing. This issue affects Diff versions: from 0.0.0 to 2.0.1, from 2.1.0 to 2.1.1.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 76%)
CISA exploited list	No
Weakness	CWE-863
Published	2026-09-02
Last modified	2026-09-16

Publisher (CNA): Drupal.org · Vendor: diff project

Last updated 2026-09-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-02 13:18 UTCPublished CVE record published
2026-09-16 16:41 UTCUpdated Record last modified

diff project diff UPGRADE

Affected: < 2.0.1 · >= 5.x-1.0 and <= 5.x-2.1 · >= 6.x-1.0 and <= 6.x-2.3 · >= 7.x-3.0 and <= 7.x-3.5 · >= 8.x-1.0 and <= 8.x-1.10 · 2.1.0 · 4.7.x-1.1

Fixed in: 2.0.1

Safe to downgrade to: a release before 2.1.0

1. Check installed version

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

2. UPGRADE to 2.0.1 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade diff

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 2.1.0 (Debian / Ubuntu)

apt-cache madison diff sudo apt install diff=<VERSION_BEFORE_2.1.0> sudo apt-mark hold diff

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

dnf --showduplicates list diff sudo dnf downgrade diff-<VERSION_BEFORE_2.1.0> sudo dnf versionlock add diff

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-2026-73478?

diff: upgrade to 2.0.1. Exact commands for each OS are on this page.

Is CVE-2026-73478 being exploited?

CVE-2026-73478 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-2026-73478 affect?

CVE-2026-73478 affects diff. Severity is medium (CVSS 5.3). Incorrect Authorization vulnerability in Drupal Diff allows Forceful Browsing. This issue affects Diff versions: from 0.0.0 to 2.0.1, from 2.1.0 to 2.1.1.

How urgent is CVE-2026-73478?

Priority 30/100. Remotely exploitable, no login, no user action

Software pages

Drupal vulnerabilities

References

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