OPNsense < 26.1.9 Stored XSS via Firewall Rule Description Field
OPNsense before 26.1.9 contains a stored cross-site scripting vulnerability that allows authenticated attackers with firewall rule management privileges to inject arbitrary HTML or JavaScript by embedding payloads in the firewall rule description field via the filter API endpoint. The unsanitized description value is persisted and later rendered through the default cell formatter in opnsense_bootgrid.js, which assigns raw cell content to innerHTML, causing injected scripts to execute in the browser of any authenticated user who views the Firewall Rules page, enabling session hijacking or credential theft.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-49131
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 15:28 UTC · Revision 1
Source evidence
OPNsense < 26.1.9 Stored XSS via Firewall Rule Description Field
core-osv · Original sourcePublished 3 Aug 2026, 20:29 UTC
OPNsense before 26.1.9 contains a stored cross-site scripting vulnerability that allows authenticated attackers with firewall rule management privileges to inject arbitrary HTML or JavaScript by embedding payloads in the firewall rule description field via the filter API endpoint. The unsanitized description value is persisted and later rendered through the default cell formatter in opnsense_bootgrid.js, which assigns raw cell content to innerHTML, causing injected scripts to execute in the browser of any authenticated user who views the Firewall Rules page, enabling session hijacking or credential theft.
osv:CVE-2026-49131
Complete source record
{
"id": "eec7cf4123f4f688d8f102bd91c231670171d32c46ee3f9327ee8c1a869dc1a8",
"url": "https://osv.dev/vulnerability/CVE-2026-49131",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "OPNsense < 26.1.9 Stored XSS via Firewall Rule Description Field",
"summary": "OPNsense before 26.1.9 contains a stored cross-site scripting vulnerability that allows authenticated attackers with firewall rule management privileges to inject arbitrary HTML or JavaScript by embedding payloads in the firewall rule description field via the filter API endpoint. The unsanitized description value is persisted and later rendered through the default cell formatter in opnsense_bootgrid.js, which assigns raw cell content to innerHTML, causing injected scripts to execute in the browser of any authenticated user who views the Firewall Rules page, enabling session hijacking or credential theft.",
"evidence": "osv:CVE-2026-49131",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2026-49131",
"aliases": [
"CVE-2026-49131"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/opnsense/core",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "b11d6b340716e240868ab19a369e058a46f0876f"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "26.1.9"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"range": [
{
"fixed": "b11d6b340716e240868ab19a369e058a46f0876f"
}
],
"source": "REFERENCES_COMMIT"
},
{
"range": [
{
"introduced": "0"
},
{
"fixed": "26.1.9"
}
],
"source": "DESCRIPTION"
}
]
}
}
],
"versions": [
"26.1.8",
"26.1.6",
"26.1.7",
"26.1.5",
"26.1.4",
"26.1.3",
"26.1.2",
"26.1.1",
"26.1",
"26.1.r2",
"26.1.r1",
"26.1.r",
"26.1.b",
"26.1.a",
"25.7.r",
"25.7.b",
"25.7.a",
"25.1.r",
"25.1.b",
"25.1.a",
"24.7.r",
"24.7.b",
"24.7.a",
"24.1.r",
"24.1.b",
"24.1.a",
"23.7.r",
"23.7.b",
"23.7.a",
"23.1.r",
"23.1.b",
"23.1.a",
"22.7.r",
"22.7.b",
"22.7.a",
"22.1.r",
"22.1.b",
"22.1.a",
"21.7.r",
"21.7.b",
"21.7.a",
"21.1.r",
"21.1.b",
"21.1.a",
"20.7.r",
"20.7.b",
"20.7.a",
"20.1.r",
"20.1.b",
"20.1.a",
"19.7.r",
"19.7.b",
"19.7.a",
"19.1.r",
"19.1.b",
"19.1.a",
"18.7.r",
"18.7.b",
"18.7.a",
"18.1.r",
"18.1.b",
"18.1.a",
"17.7.r",
"17.7.b",
"17.7.a",
"17.1.r",
"17.1.b",
"17.1.a",
"16.7.r",
"16.7.b",
"16.7.a",
"15.7",
"15.1.12",
"15.1.11.4",
"15.1.11.3",
"15.1.11.2",
"15.1.11.1",
"15.1.11",
"15.1.10.2",
"15.1.10",
"15.1.9.2",
"15.1.9.1",
"15.1.9",
"15.1.8.4",
"15.1.8.3",
"15.1.8.2",
"15.1.8.1",
"15.1.8",
"15.1.7.2",
"15.1.7.1",
"15.1.7",
"15.1.6.1",
"15.1.6",
"15.1.5",
"15.1.4",
"15.1.3",
"15.1.2",
"15.1.1",
"15.1"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49131.json"
}
}
],
"modified": "2026-10-28T02:30:29.829277675Z",
"provider": "osv",
"references": [
"https://docs.opnsense.org/releases/CE_26.1.html#june-02-2026",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49131.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-49131",
"https://www.vulncheck.com/advisories/opnsense-stored-xss-via-firewall-rule-description-field",
"https://github.com/opnsense/core/commit/b11d6b340716e240868ab19a369e058a46f0876f",
"https://github.com/opnsense/core"
],
"provider_metadata": {
"cwe_ids": [
"CWE-79"
],
"cna_assigner": "VulnCheck",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49131.json"
}
},
"related_cves": [
{
"value": "CVE-2026-49131",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 496824,
"published_at": "2026-08-03T20:29:48.071+00:00"
}