Label Studio through 1.23.0 fails to validate webhook URLs, allowing authenticated users to dispatch requests to internal services including RFC 1918 addresses and cloud metadata endpoints. Attackers can create webhooks targeting private networks and exfiltrate annotation data by enabling payload transmission in outbound requests.
https://www.vulncheck.com/advisories/label-studio-through-1.23.0-ssrf-via-unvalidated-webhook-url
https://github.com/HumanSignal/label-studio/issues/9801
https://github.com/HumanSignal/label-studio/commit/2c1c1d6472153032af8ed399168f814bea854e3e
https://github.com/HumanSignal/label-studio/blob/1.23.0/label_studio/webhooks/utils.py
Published: 2026-09-03
Updated: 2026-09-05
Base Score: 7.5
Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:P/A:N
Severity: High
Base Score: 8.5
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
Severity: High
Base Score: 8.4
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N
Severity: High
EPSS: 0.0023