High severity · published Oct 27, 2026
CVE-2026-58205
GRR has a Reflected XSS issue
New
8.1
CVSS
0.3%
EPSS
No
On KEV
Description
GRR is a resource management and reservation application. Prior to version 4.5.0, `maj.php` reflects the `forcemaj` parameter without adequate escaping when installation files remain accessible. Removal of these files is not automatic. An attacker can craft a URL that executes arbitrary JavaScript in a victim's browser when the victim accesses it. This reflected cross-site scripting can enable phishing, redirection to malicious sites, cookie theft and session hijacking because the authentication cookie is not `HttpOnly`. This issue is fixed in version 4.5.0.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GR
GRR · JeromeDevome
< 4.5.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-58205
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-58205
github.com
https://github.com/JeromeDevome/GRR/commit/4ef77f91818215c1f8e0f06023d89257dfd61c68
github.com
https://github.com/JeromeDevome/GRR/security/advisories/GHSA-r6x2-w38j-vvq2
github.com
https://github.com/JeromeDevome/GRR/tree/v4.5.0
More from GRR
9.1
CVE-2026-58256
GRR vulnerable to Remote Code Execution Via PHP Code Injection
7.2
CVE-2026-58257
GRR vulnerable to Arbitrary File Read and Deletion
