CVE-2026-33544: Tinyauth is an authentication and authorization server

Q: How do I fix CVE-2026-33544?

tinyauth: upgrade to 5.0.5. Exact commands for each OS are on this page.

Q: Is CVE-2026-33544 being exploited?

CVE-2026-33544 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-2026-33544 affect?

CVE-2026-33544 affects tinyauth. Severity is high (CVSS 7.7). Tinyauth is an authentication and authorization server. Prior to version 5.0.5, all three OAuth service implementations (GenericOAuthService, GithubOAuthService, GoogleOAuthService) store PKCE verifiers and access tokens as mutable struct f

Q: How urgent is CVE-2026-33544?

Priority 39/100. High severity; Public exploit reference

Routine

HIGH 7.7UPGRADE

CVE-2026-33544 is a high-severity flaw (CVSS 7.7) affecting tinyauth. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Tinyauth is an authentication and authorization server. Prior to version 5.0.5, all three OAuth service implementations (GenericOAuthService, GithubOAuthService, GoogleOAuthService) store PKCE verifiers and access tokens as mutable struct fields on singleton instances shared across all concurrent requests. When two users initiate OAuth login for the same provider concurrently, a race condition between VerifyCode() and Userinfo() causes one user t

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	7.7 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.3% (top 73%)
CISA exploited list	No
Weakness	CWE-362
Published	2026-04-02
Last modified	2026-10-26

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

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-02 15:16 UTCPublished CVE record published
2026-10-26 22:10 UTCUpdated Record last modified

tinyauth tinyauth UPGRADE

Affected: < 5.0.5

Fixed in: 5.0.5

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 5.0.5 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tinyauth

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-2026-33544?

tinyauth: upgrade to 5.0.5. Exact commands for each OS are on this page.

Is CVE-2026-33544 being exploited?

CVE-2026-33544 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-2026-33544 affect?

CVE-2026-33544 affects tinyauth. Severity is high (CVSS 7.7). Tinyauth is an authentication and authorization server. Prior to version 5.0.5, all three OAuth service implementations (GenericOAuthService, GithubOAuthService, GoogleOAuthService) store PKCE verifiers and access tokens as mutable struct f

How urgent is CVE-2026-33544?

Priority 39/100. High severity; Public exploit reference

References

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