canto-saas-api: Authenticated API requests can be redirected via unencoded path variables

published 2026-06-19 4 mo ago modified 2026-09-30 39 d ago also GHSA-9qfv-wgh2-m6p8 , EUVD-2026-78905

cvss: 4.8; 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 29%
public exploits: 0; none known

canto-saas-api is a PHP library for interacting with the Canto SaaS API. Prior to version 3.0.0, Request::buildRequestUrl() joins values returned by Request::getPathVariables() without encoding individual path segments, including the scheme and contentId values used by GetContentDetailsRequest. When a consuming application supplies an untrusted path variable value, path traversal sequences, query delimiters, or fragment delimiters can change the destination endpoint before AbstractEndpoint::sendRequest() attaches the configured authentication token. An attacker who controls that path variable value through the consuming application can cause unintended reads or writes with the configured application's privileges on the same Canto instance, but applications that pass only trusted and validated identifiers are not exploitable. This issue is fixed in version 3.0.0.

Patch / fix

fixed in 1 links 2

packagist jleehr/canto-saas-api 3.0.0

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 54 d ago (2026-09-15)

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.8	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
GitHub	3.1	4.8	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
packagist	jleehr/canto-saas-api	<3.0.0	3.0.0

Affected products

jleehr canto-saas-api

Classification

Weakness

CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component
CWE-918 Server-Side Request Forgery

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