CVE-2019-12300: Buildbot before 1.8.2 and 2.x before 2.3.1 accepts a user-submitted authorization token from OAuth and uses it

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CRITICAL 9.8REMOTEUPGRADE

CVE-2019-12300 is a critical-severity flaw (CVSS 9.8) affecting buildbot. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buildbot before 1.8.2 and 2.x before 2.3.1 accepts a user-submitted authorization token from OAuth and uses it to authenticate a user. If an attacker has a token allowing them to read the user details of a victim, they can login as the victim.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.8% (top 21%)
CISA exploited list	No
Weakness	CWE-287
Published	2019-05-23
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: buildbot

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

Am I affected?

Timeline

2019-05-23 15:30 UTCPublished CVE record published
2026-06-17 02:14 UTCUpdated Record last modified

buildbot buildbot UPGRADE

Affected: < 1.8.2 · >= 2.0.0 and < 2.3.1

Fixed in: 1.8.2, 2.3.1

Safe to downgrade to: a release before 2.0.0

1. Check installed version

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

2. UPGRADE to 1.8.2 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade buildbot

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 buildbot sudo apt install buildbot=<VERSION_BEFORE_2.0.0> sudo apt-mark hold buildbot

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

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

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-2019-12300?

buildbot: upgrade to 1.8.2, 2.3.1. Exact commands for each OS are on this page.

Is CVE-2019-12300 being exploited?

CVE-2019-12300 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-2019-12300 affect?

CVE-2019-12300 affects buildbot. Severity is critical (CVSS 9.8). Buildbot before 1.8.2 and 2.x before 2.3.1 accepts a user-submitted authorization token from OAuth and uses it to authenticate a user. If an attacker has a token allowing them to read the user details of a victim, they can login as the vict

How urgent is CVE-2019-12300?

Priority 59/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2019-7313 MEDIUM 6.1 UPGRADE www/resource.py in Buildbot before 1.8.1 allows CRLF injection in the Location header of /auth/login and /auth

References

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