CVE-2026-28681: Internet Routing Registry daemon version 4 is an IRR database server, processing IRR objects in the RPSL forma

Routine

HIGH 8.1UPGRADE

CVE-2026-28681 is a high-severity flaw (CVSS 8.1) affecting internet routing registry daemon. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Internet Routing Registry daemon version 4 is an IRR database server, processing IRR objects in the RPSL format. From version 4.4.0 to before version 4.4.5 and from version 4.5.0 to before version 4.5.1, an attacker can manipulate the HTTP Host header on a password reset or account creation request. The confirmation link in the resulting email can then point to an attacker-controlled domain. Opening the link in the email is sufficient to pass the

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 61%)
CISA exploited list	No
Weakness	CWE-601, CWE-640
Published	2026-03-06
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: internet routing registry daemon project

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

Am I affected?

Timeline

2026-03-06 05:16 UTCPublished CVE record published
2026-06-17 10:28 UTCUpdated Record last modified

internet routing registry daemon project internet routing registry daemon UPGRADE

Affected: >= 4.4.0 and < 4.4.5 · >= 4.5.0 and < 4.5.1

Fixed in: 4.4.5, 4.5.1

Safe to downgrade to: a release before 4.4.0

1. Check installed version

apt-cache policy internet-routing-registry-daemon || rpm -q internet-routing-registry-daemon || internet-routing-registry-daemon --version

2. UPGRADE to 4.4.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade internet-routing-registry-daemon

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade internet-routing-registry-daemon

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 4.4.0 (Debian / Ubuntu)

apt-cache madison internet-routing-registry-daemon sudo apt install internet-routing-registry-daemon=<VERSION_BEFORE_4.4.0> sudo apt-mark hold internet-routing-registry-daemon

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

dnf --showduplicates list internet-routing-registry-daemon sudo dnf downgrade internet-routing-registry-daemon-<VERSION_BEFORE_4.4.0> sudo dnf versionlock add internet-routing-registry-daemon

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-2026-28681?

internet routing registry daemon: upgrade to 4.4.5, 4.5.1. Exact commands for each OS are on this page.

Is CVE-2026-28681 being exploited?

CVE-2026-28681 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-2026-28681 affect?

CVE-2026-28681 affects internet routing registry daemon. Severity is high (CVSS 8.1). Internet Routing Registry daemon version 4 is an IRR database server, processing IRR objects in the RPSL format. From version 4.4.0 to before version 4.4.5 and from version 4.5.0 to before version 4.5.1, an attacker can manipulate the HTTP

How urgent is CVE-2026-28681?

Priority 38/100. High severity

References

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