Data exfiltration via AI plugin Jira tool

published 2025-04-16 18 mo ago modified 2026-09-10 1 mo ago also GHSA-9h6j-4ffx-cm84 , GO-2025-3622 , EUVD-2025-11357

cvss: 3.0; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits: 0; none known

Mattermost versions 10.4.x <= 10.4.2, 10.5.x <= 10.5.0, 9.11.x <= 9.11.9 fail to restrict domains the LLM can request to contact upstream which allows an authenticated user to exfiltrate data from an arbitrary server accessible to the victim via performing a prompt injection in the AI plugin's Jira tool.

Patch / fix

fixed in 3 distros 1

go github.com/mattermost/mattermost/server/v8 8.0.0-20250218121836-2b5275d87136, 9.11.10, 10.4.3, 10.5.1
go github.com/mattermost/mattermost-server 9.11.10+incompatible, 10.4.3+incompatible, 10.5.1+incompatible
Mattermost Mattermost 9.11.10, 10.4.3, 10.5.1, 10.6.0

govulncheck-vulndb openSUSE Tumbleweed 0.0.20250422T181640-1.1

opensuse advisories openSUSE-SU-2025:15017-1

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 18 mo ago (2025-04-16)

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	3.0	CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:N/A:N
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
GitHub	3.1	3.0	CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
go	github.com/mattermost/mattermost/server/v8	>=10.5.0, <10.5.1 >=10.4.0, <10.4.3 >=9.11.0, <9.11.10 <8.0.0-20250218121836-2b5275d87136	10.5.1 10.4.3 9.11.10 8.0.0-20250218121836-2b5275d87136
go	github.com/mattermost/mattermost-server	>=9.11.0+incompatible, <9.11.10+incompatible >=10.4.0+incompatible, <10.4.3+incompatible >=10.5.0+incompatible, <10.5.1+incompatible	9.11.10+incompatible 10.4.3+incompatible 10.5.1+incompatible
go	github.com/mattermost/mattermost-server/v5	all versions	no fix listed
go	github.com/mattermost/mattermost-server/v6	all versions	no fix listed

Affected products

Mattermost Mattermost

Classification

Weakness

CWE-1426 Improper Validation of Generative AI Output
CWE-201 Insertion of Sensitive Information Into Sent Data
CWE-497 Exposure of Sensitive System Information to an Unauthorized Control Sphere

References

mattermost.com /security-updates
web, vendor-advisory
nvd.nist.gov /vuln/detail/CVE-2025-31363
advisory
github.com /mattermost/mattermost
package
pkg.go.dev /vuln/GO-2025-3622
web
github.com /advisories/GHSA-9h6j-4ffx-cm84
advisory

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