Hatchet: Cross-tenant durable callback payload disclosure in Hatchet V1 Dispatcher

published 2026-09-21 49 d ago modified 2026-10-01 38 d ago also EUVD-2026-83979 , GHSA-9q4h-f4x5-ffq8 , GO-2026-6561

cvss: 3.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits: 0; none known

Hatchet is a platform for orchestrating background tasks, AI agents, and durable workflows at scale. Prior to 0.95.3, the V1 DurableTask stream handler stores worker-supplied task_external_id values in the durableInvocations routing map before tenant ownership is verified, and callback delivery resolves that map by task UUID without tenant identity. An authenticated tenant worker that knows another tenant's durable task UUID and keeps a stream open on the same dispatcher process can receive that task's durable callback result payload. UUIDv4 values are not enumerable, and single-tenant deployments are unaffected in practice. This issue is fixed in version 0.95.3.

Patch / fix

fixed in 2 links 1

go github.com/hatchet-dev/hatchet 0.95.3
hatchet hatchet 0.95.3

github.com/hatchet-dev/hatchet@9555bfd commit

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 48 d ago (2026-09-21)

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	3.1	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
GitHub	3.1	3.1	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
go	github.com/hatchet-dev/hatchet	<0.95.3	0.95.3

Affected products

hatchet-dev hatchet

Classification

Weakness

CWE-639 Authorization Bypass Through User-Controlled Key
CWE-862 Missing Authorization

References

github.com /hatchet-dev/hatchet/commit/9555bfdd1e97f61d25e614ccaa107c5fb7dc4976
web, patch
github.com /hatchet-dev/hatchet/security/advisories/GHSA-9q4h-f4x5-ffq8
web, advisory
nvd.nist.gov /vuln/detail/CVE-2026-84298
advisory
github.com /hatchet-dev/hatchet
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary