CVE-2026-49131

MEDIUMPre-NVD 5.45.4—
EchelonGraph scoreHIGH confidence

Score 5.4 from GitHub Security Advisory published 2026-08-03. the CNA's CVSS baseline 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 3 sources updated this week
5.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.4Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
5.4
EG Score
5.4(high)
EG Risk
24(Track)
EG Risk 24/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity54% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

August 3, 2026

Last Modified

August 14, 2026

Advisory Details (3)

Auto-updated Aug 3, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
generic

OPNsense < 26.1.9 Stored XSS via Firewall Rule Description Field | Advisories | VulnCheck

https://www.vulncheck.com/advisories/opnsense-stored-xss-via-firewall-rule-description-field
github_commit

commit b11d6b340716 (opnsense/core)

Fix landed in opnsense/core commit b11d6b340716 — awaiting tagged release

https://github.com/opnsense/core/commit/b11d6b340716e240868ab19a369e058a46f0876f
generic

26.1 “Witty Woodpecker” Series — OPNsense documentation

https://docs.opnsense.org/releases/CE_26.1.html#june-02-2026

Vendor Advisories for CVE-2026-49131(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 23× in last 7d / 50× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-21 05:31 UTCEG score recompute
  2. 2026-08-21 05:31 UTCGHSA enrichment
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-20 03:27 UTCEG score recompute
  5. 2026-08-20 03:27 UTCGHSA enrichment
  6. 2026-08-19 17:04 UTCEPSS rescore
  7. 2026-08-19 01:24 UTCEG score recompute
  8. 2026-08-19 01:24 UTCGHSA enrichment
  9. 2026-08-18 13:48 UTCEPSS rescore
  10. 2026-08-17 23:21 UTCEG score recompute
  11. 2026-08-17 23:21 UTCGHSA enrichment
  12. 2026-08-17 13:47 UTCEPSS rescore
  13. 2026-08-16 21:18 UTCEG score recompute
  14. 2026-08-16 21:18 UTCGHSA enrichment
  15. 2026-08-16 14:56 UTCEPSS rescore
  16. 2026-08-16 02:14 UTCEPSS rescore
  17. 2026-08-15 19:15 UTCEG score recompute
  18. 2026-08-15 19:15 UTCGHSA enrichment
  19. 2026-08-15 01:30 UTCEPSS rescore
  20. 2026-08-14 17:11 UTCEG score recompute
  21. 2026-08-14 17:11 UTCGHSA enrichment
  22. 2026-08-14 09:49 UTCEG score recompute
  23. 2026-08-14 09:49 UTCGHSA enrichment
  24. 2026-08-13 22:00 UTCEPSS rescore
  25. 2026-08-13 07:46 UTCEG score recompute
Show 25 more
  1. 2026-08-13 07:46 UTCGHSA enrichment
  2. 2026-08-12 13:51 UTCEPSS rescore
  3. 2026-08-12 05:42 UTCEG score recompute
  4. 2026-08-12 05:42 UTCGHSA enrichment
  5. 2026-08-11 03:39 UTCEG score recompute
  6. 2026-08-11 03:39 UTCGHSA enrichment
  7. 2026-08-11 00:00 UTCEPSS rescore
  8. 2026-08-10 01:36 UTCEG score recompute
  9. 2026-08-10 01:36 UTCGHSA enrichment
  10. 2026-08-09 13:46 UTCEPSS rescore
  11. 2026-08-08 23:33 UTCGHSA enrichment
  12. 2026-08-07 21:29 UTCEG score recompute
  13. 2026-08-07 21:29 UTCGHSA enrichment
  14. 2026-08-06 19:26 UTCEG score recompute
  15. 2026-08-06 19:26 UTCGHSA enrichment
  16. 2026-08-05 19:17 UTCEPSS rescore
  17. 2026-08-05 17:23 UTCGHSA enrichment
  18. 2026-08-04 15:20 UTCEG score recompute
  19. 2026-08-04 15:20 UTCGHSA enrichment
  20. 2026-08-04 15:10 UTCEPSS rescore
  21. 2026-08-04 14:49 UTCEG score recompute
  22. 2026-08-04 14:49 UTCGHSA enrichment
  23. 2026-08-03 21:20 UTCEG score recompute
  24. 2026-08-03 20:43 UTCEG score recompute
  25. 2026-08-03 20:43 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-49131?
CVE-2026-49131 is a medium vulnerability published on August 3, 2026. 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…
When was CVE-2026-49131 disclosed?
CVE-2026-49131 was first published in the National Vulnerability Database on August 3, 2026, with the most recent update on August 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-49131 actively exploited?
CVE-2026-49131 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 93.7% of all scored CVEs.
What is the CVSS score of CVE-2026-49131?
CVE-2026-49131 has a CVSS v4.0 base score of 5.4 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-49131?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-49131, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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