CVE-2021-26928: BIRD through 2.0.7 does not provide functionality for password authentication of BGP peers

Q: How do I fix CVE-2021-26928?

bird: upgrade to newer than 2.0.7. Exact commands for each OS are on this page.

Q: Is CVE-2021-26928 being exploited?

CVE-2021-26928 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-26928 affect?

CVE-2021-26928 affects bird. Severity is medium (CVSS 6.8). BIRD through 2.0.7 does not provide functionality for password authentication of BGP peers. Because of this, products that use BIRD (which may, for example, include Tigera products in some configurations, as well as products of other vendor

Q: How urgent is CVE-2021-26928?

Priority 45/100. Public exploit reference

This month

MEDIUM 6.8UPGRADE

CVE-2021-26928 is a medium-severity flaw (CVSS 6.8) affecting bird. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

BIRD through 2.0.7 does not provide functionality for password authentication of BGP peers. Because of this, products that use BIRD (which may, for example, include Tigera products in some configurations, as well as products of other vendors) may have been susceptible to route redirection for Denial of Service and/or Information Disclosure. NOTE: a researcher has asserted that the behavior is within Tigera’s area of responsibility; however, Tiger

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.8 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.0% (top 37%)
CISA exploited list	No
Weakness	CWE-306
Published	2021-06-04
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: nic

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

Am I affected?

Timeline

2021-06-04 21:15 UTCPublished CVE record published
2026-06-17 03:44 UTCUpdated Record last modified

nic bird UPGRADE

Affected: <= 2.0.7

Fixed in: newer than 2.0.7

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 2.0.7 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade bird

Note

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

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-2021-26928?

bird: upgrade to newer than 2.0.7. Exact commands for each OS are on this page.

Is CVE-2021-26928 being exploited?

CVE-2021-26928 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-2021-26928 affect?

CVE-2021-26928 affects bird. Severity is medium (CVSS 6.8). BIRD through 2.0.7 does not provide functionality for password authentication of BGP peers. Because of this, products that use BIRD (which may, for example, include Tigera products in some configurations, as well as products of other vendor

How urgent is CVE-2021-26928?

Priority 45/100. Public exploit reference

Related CVEs

CVE-2018-12066 MEDIUM 5.5 UPGRADE BIRD Internet Routing Daemon before 1.6.4 allows local users to cause a denial of service (stack consumption a

References

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