Spree: Broken Access Control in `PATCH /api/v3/store/carts/:id/associate` (IDOR)

published 2026-09-22 47 d ago modified 2026-09-23 46 d ago also GHSA-4825-p4xm-pcf2 , EUVD-2026-84794

cvss: 7.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits: 0; none known

Spree is an open source e-commerce solution built with Ruby on Rails. From 5.4.0 until 5.4.4 and 5.5.4, PATCH /api/v3/store/carts/:id/associate in Spree::Api::V3::Store::CartsController#associate uses find_cart_for_association to locate a cart by prefixed_id but does not require a cart token or otherwise verify possession of the selected guest cart. An authenticated customer can derive reversible prefixed cart IDs, associate an eligible guest cart with the attacker's account, and receive billing and shipping address data from the cart. Exploitation requires a guest cart with address data on a store that does not require login for checkout, and reassignment can also disrupt the guest's in-progress cart. This issue is fixed in versions 5.4.4 and 5.5.4.

Patch / fix

fixed in 1 links 5

rubygems spree_api 5.4.4, 5.5.4

github.com/spree/spree@8834230 commit
github.com/spree/spree@af0d1a2 commit
github.com/spree/spree#14314 pull request
github.com/spree/spree/releases/tag/v5.4.4 release
github.com/spree/spree/releases/tag/v5.5.4 release

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 47 d ago (2026-09-22)

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/spree/spree/security/advisories/GHSA-4825-p4xm-pcf2 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
GitHub	3.1	7.1	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
rubygems	spree_api	>=5.4.0, <5.4.4 >=5.5.0, <5.5.4	5.4.4 5.5.4

Affected products

spree spree

Classification

Weakness

CWE-639 Authorization Bypass Through User-Controlled Key

References

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.

Summary