CVE-2026-23991: go-tuf is a Go implementation of The Update Framework (TUF)

Routine

MEDIUM 5.9REMOTEUPGRADE

CVE-2026-23991 is a medium-severity flaw (CVSS 5.9) affecting go-tuf. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

go-tuf is a Go implementation of The Update Framework (TUF). Starting in version 2.0.0 and prior to version 2.3.1, if the TUF repository (or any of its mirrors) returns invalid TUF metadata JSON (valid JSON but not well formed TUF metadata), the client will panic during parsing, causing a denial of service. The panic happens before any signature is validated. This means that a compromised repository/mirror/cache can DoS clients without having acc

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 52%)
CISA exploited list	No
Weakness	CWE-617, CWE-754
Published	2026-01-22
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: theupdateframework

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-01-22 03:15 UTCPublished CVE record published
2026-06-17 10:22 UTCUpdated Record last modified

theupdateframework go-tuf UPGRADE

Affected: >= 2.0.0 and < 2.3.1

Fixed in: 2.3.1

Safe to downgrade to: a release before 2.0.0

1. Check installed version

apt-cache policy go-tuf || rpm -q go-tuf || go-tuf --version

2. UPGRADE to 2.3.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade go-tuf

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade go-tuf

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 2.0.0 (Debian / Ubuntu)

apt-cache madison go-tuf sudo apt install go-tuf=<VERSION_BEFORE_2.0.0> sudo apt-mark hold go-tuf

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

dnf --showduplicates list go-tuf sudo dnf downgrade go-tuf-<VERSION_BEFORE_2.0.0> sudo dnf versionlock add go-tuf

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-2026-23991?

go-tuf: upgrade to 2.3.1. Exact commands for each OS are on this page.

Is CVE-2026-23991 being exploited?

CVE-2026-23991 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-2026-23991 affect?

CVE-2026-23991 affects go-tuf. Severity is medium (CVSS 5.9). go-tuf is a Go implementation of The Update Framework (TUF). Starting in version 2.0.0 and prior to version 2.3.1, if the TUF repository (or any of its mirrors) returns invalid TUF metadata JSON (valid JSON but not well formed TUF metadata)

How urgent is CVE-2026-23991?

Priority 38/100. Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-24686 MEDIUM 4.7 UPGRADE go-tuf is a Go implementation of The Update Framework (TUF)
CVE-2026-23992 MEDIUM 5.9 UPGRADE go-tuf is a Go implementation of The Update Framework (TUF)

References

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