CVE-2019-17268: The omniauth-weibo-oauth2 gem 0.4.6 for Ruby, as distributed on RubyGems.org, included a code-execution backdo

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2019-17268 is a critical-severity flaw (CVSS 9.8) affecting omniauth-weibo-oauth2. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The omniauth-weibo-oauth2 gem 0.4.6 for Ruby, as distributed on RubyGems.org, included a code-execution backdoor inserted by a third party. Versions through 0.4.5, and 0.5.1 and later, are unaffected.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Weakness	CWE-94
Published	2020-02-07
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: omniauth-weibo-oauth2 project

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

Am I affected?

Timeline

2020-02-07 14:15 UTCPublished CVE record published
2026-06-17 02:23 UTCUpdated Record last modified

omniauth-weibo-oauth2 project omniauth-weibo-oauth2 DOWNGRADE

Affected: 0.4.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.4.6

1. Check installed version

apt-cache policy omniauth-weibo-oauth2 || rpm -q omniauth-weibo-oauth2 || omniauth-weibo-oauth2 --version

2. No fixed release: DOWNGRADE to a release before 0.4.6 (Debian / Ubuntu)

apt-cache madison omniauth-weibo-oauth2 sudo apt install omniauth-weibo-oauth2=<VERSION_BEFORE_0.4.6> sudo apt-mark hold omniauth-weibo-oauth2

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list omniauth-weibo-oauth2 sudo dnf downgrade omniauth-weibo-oauth2-<VERSION_BEFORE_0.4.6> sudo dnf versionlock add omniauth-weibo-oauth2

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-2019-17268?

omniauth-weibo-oauth2: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2019-17268 being exploited?

CVE-2019-17268 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-2019-17268 affect?

CVE-2019-17268 affects omniauth-weibo-oauth2. Severity is critical (CVSS 9.8). The omniauth-weibo-oauth2 gem 0.4.6 for Ruby, as distributed on RubyGems.org, included a code-execution backdoor inserted by a third party. Versions through 0.4.5, and 0.5.1 and later, are unaffected.

How urgent is CVE-2019-17268?

Priority 60/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

Ruby vulnerabilities

References

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