hatchet - Unauthenticated OAuth state CSRF / login-CSRF via empty-state collision in ValidateOAuthState

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

Hatchet is a platform for orchestrating background tasks, AI agents, and durable workflows at scale. Prior to 0.91.1, ValidateOAuthState clears the oauth_state_ session value to an empty string after a successful OAuth callback and later accepts an empty state parameter as equal, allowing an unauthenticated attacker to bind a victim's Hatchet session to an attacker-controlled OAuth identity. Exploitation requires the victim to have completed an OAuth flow in the current session and the deployment to enable auth.google.enabled, auth.github.enabled, or the Slack integration. This issue is fixed in version 0.91.1.

Source published

21 Sep 2026 15:45:27 UTC

Source modified

21 Sep 2026 20:45:49 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N

Hatchet is a platform for orchestrating background tasks, AI agents, and durable workflows at scale. Prior to 0.91.1, ValidateOAuthState clears the oauth_state_ session value to an empty string after a successful OAuth callback and later accepts an empty state parameter as equal, allowing an unauthenticated attacker to bind a victim's Hatchet session to an attacker-controlled OAuth identity. Exploitation requires the victim to have completed an OAuth flow in the current session and the deployment to enable auth.google.enabled, auth.github.enabled, or the Slack integration. This issue is fixed in version 0.91.1.

Source published

Sep 21, 2026, 3:45:27 PM (timezone not stated)

Source modified

Sep 21, 2026, 8:45:49 PM (timezone not stated)

Observed here

9 Nov 2026 14:10:24 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N

Hatchet is a platform for orchestrating background tasks, AI agents, and durable workflows at scale. Prior to 0.91.1, ValidateOAuthState clears the oauth_state_ session value to an empty string after a successful OAuth callback and later accepts an empty state parameter as equal, allowing an unauthenticated attacker to bind a victim's Hatchet session to an attacker-controlled OAuth identity. Exploitation requires the victim to have completed an OAuth flow in the current session and the deployment to enable auth.google.enabled, auth.github.enabled, or the Slack integration. This issue is fixed in version 0.91.1.

Source published

21 Sep 2026 16:17:09 UTC

Source modified

24 Sep 2026 21:25:27 UTC

Observed here

25 Oct 2026 14:19:22 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N

### Summary Hatchet version v0.86.26 and below is vulnerable to OAuth state CSRF (login CSRF / account fixation). The vulnerable code clears the session `oauth_state_<integration>` value to the empty string `""` after a successful OAuth callback rather than removing the key, and the subsequent state-equality check then accepts an empty `?state=` parameter on any later callback request — allowing an unauthenticated attacker to bind an already-authenticated victim's session cookie to an attacker-controlled OAuth identity (account takeover via login-CSRF). ### Impact Affected configurations: any deployment that has enabled at least one of `auth.google.enabled`, `auth.github.enabled`, or the Slack integration, and where the victim has completed at least one OAuth flow on that integration in the current session. Bug present on `main` HEAD and in every tagged release up to and including v0.86.26 (commit `243f41d9e1161e70d47dfc0a6509f1c4ddfc9c23`).

Source published

21 Sep 2026 15:47:01 UTC

Source modified

4 Nov 2026 23:45:05 UTC

Observed here

4 Nov 2026 23:56:21 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N

Publisher rating · HIGH

Unauthenticated OAuth state CSRF via empty-state collision in ValidateOAuthState in github.com/hatchet-dev/hatchet

Source published

28 Sep 2026 16:43:40 UTC

Source modified

7 Oct 2026 17:45:12 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.