CVE-2026-49131

MEDIUMPre-NVD 5.45.4—
EchelonGraph scoreMEDIUM confidence

Score 5.4 from GitHub Security Advisory published 2026-08-03. A secondary CVSS source baseline 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
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: 0.3%CVSS: 5.4Exploit: None knownExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

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
5.4MEDIUMmedium confidence
EG Risk
24
EG Risk 24/100CISA SSVC

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%
CISA SSVC: Track at every mission impact level.
Action: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.
EPSS PROB
0.3%
EPSS %ILE
19th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 3, 2026

Last Modified

September 16, 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 12× in last 7d / 61× 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.

Showing the most recent 100 of 146 total refreshes for this CVE.

  1. 2026-10-04 23:22 UTCEPSS rescore
  2. 2026-10-04 06:17 UTCEG score recompute
  3. 2026-10-04 06:17 UTCGHSA enrichment
  4. 2026-10-03 14:25 UTCEPSS rescore
  5. 2026-10-02 10:17 UTCEG score recompute
  6. 2026-10-02 10:17 UTCGHSA enrichment
  7. 2026-10-01 19:50 UTCEPSS rescore
  8. 2026-10-01 02:32 UTCEG score recompute
  9. 2026-10-01 02:32 UTCGHSA enrichment
  10. 2026-09-30 15:03 UTCEPSS rescore
  11. 2026-09-29 06:36 UTCEG score recompute
  12. 2026-09-29 06:36 UTCGHSA enrichment
  13. 2026-09-28 13:51 UTCEPSS rescore
  14. 2026-09-27 18:14 UTCEG score recompute
  15. 2026-09-27 18:14 UTCGHSA enrichment
  16. 2026-09-27 13:48 UTCEPSS rescore
  17. 2026-09-26 15:59 UTCEPSS rescore
  18. 2026-09-26 00:27 UTCEPSS rescore
  19. 2026-09-25 10:15 UTCEG score recompute
  20. 2026-09-25 10:15 UTCGHSA enrichment
  21. 2026-09-24 08:12 UTCEG score recompute
  22. 2026-09-24 08:12 UTCGHSA enrichment
  23. 2026-09-23 17:53 UTCEPSS rescore
  24. 2026-09-23 05:57 UTCEG score recompute
  25. 2026-09-23 05:57 UTCGHSA enrichment
Show 75 more
  1. 2026-09-22 03:53 UTCEG score recompute
  2. 2026-09-22 03:53 UTCGHSA enrichment
  3. 2026-09-20 20:16 UTCEPSS rescore
  4. 2026-09-20 05:46 UTCEG score recompute
  5. 2026-09-20 05:46 UTCGHSA enrichment
  6. 2026-09-19 03:43 UTCEG score recompute
  7. 2026-09-19 03:43 UTCGHSA enrichment
  8. 2026-09-18 19:28 UTCEPSS rescore
  9. 2026-09-18 01:10 UTCEG score recompute
  10. 2026-09-18 01:10 UTCGHSA enrichment
  11. 2026-09-16 21:11 UTCEG score recompute
  12. 2026-09-16 21:11 UTCGHSA enrichment
  13. 2026-09-16 14:08 UTCEPSS rescore
  14. 2026-09-16 05:18 UTCEG score recompute
  15. 2026-09-16 05:18 UTCGHSA enrichment
  16. 2026-09-16 05:15 UTCEPSS rescore
  17. 2026-09-15 01:48 UTCGHSA enrichment
  18. 2026-09-13 19:36 UTCEG score recompute
  19. 2026-09-13 19:36 UTCGHSA enrichment
  20. 2026-09-13 16:47 UTCEPSS rescore
  21. 2026-09-12 16:57 UTCEG score recompute
  22. 2026-09-12 16:57 UTCGHSA enrichment
  23. 2026-09-11 14:53 UTCEG score recompute
  24. 2026-09-11 14:53 UTCGHSA enrichment
  25. 2026-09-11 14:53 UTCEPSS rescore
  26. 2026-09-10 09:35 UTCEPSS rescore
  27. 2026-09-10 08:49 UTCGHSA enrichment
  28. 2026-09-09 06:42 UTCEG score recompute
  29. 2026-09-09 06:42 UTCGHSA enrichment
  30. 2026-09-08 22:01 UTCEPSS rescore
  31. 2026-09-07 18:47 UTCEG score recompute
  32. 2026-09-07 18:47 UTCGHSA enrichment
  33. 2026-09-07 16:01 UTCEPSS rescore
  34. 2026-09-06 13:47 UTCEPSS rescore
  35. 2026-09-06 06:28 UTCEG score recompute
  36. 2026-09-06 06:28 UTCGHSA enrichment
  37. 2026-09-05 04:17 UTCEG score recompute
  38. 2026-09-05 04:17 UTCGHSA enrichment
  39. 2026-09-04 05:06 UTCEPSS rescore
  40. 2026-09-03 17:49 UTCEG score recompute
  41. 2026-09-03 17:49 UTCGHSA enrichment
  42. 2026-09-02 14:12 UTCEPSS rescore
  43. 2026-09-02 07:50 UTCEG score recompute
  44. 2026-09-02 07:50 UTCGHSA enrichment
  45. 2026-09-01 13:54 UTCEPSS rescore
  46. 2026-09-01 04:40 UTCEPSS rescore
  47. 2026-09-01 02:54 UTCGHSA enrichment
  48. 2026-08-31 00:00 UTCEG score recompute
  49. 2026-08-31 00:00 UTCGHSA enrichment
  50. 2026-08-30 19:17 UTCEPSS rescore
  51. 2026-08-30 01:22 UTCEPSS rescore
  52. 2026-08-29 21:57 UTCEG score recompute
  53. 2026-08-29 21:57 UTCGHSA enrichment
  54. 2026-08-28 21:41 UTCEPSS rescore
  55. 2026-08-27 21:14 UTCEG score recompute
  56. 2026-08-27 21:14 UTCGHSA enrichment
  57. 2026-08-27 14:25 UTCEPSS rescore
  58. 2026-08-26 19:11 UTCEG score recompute
  59. 2026-08-26 19:11 UTCGHSA enrichment
  60. 2026-08-26 14:46 UTCEPSS rescore
  61. 2026-08-25 13:49 UTCEPSS rescore
  62. 2026-08-25 13:43 UTCEG score recompute
  63. 2026-08-25 13:43 UTCGHSA enrichment
  64. 2026-08-24 11:40 UTCEG score recompute
  65. 2026-08-24 11:40 UTCGHSA enrichment
  66. 2026-08-23 09:37 UTCEG score recompute
  67. 2026-08-23 09:37 UTCGHSA enrichment
  68. 2026-08-23 00:19 UTCEPSS rescore
  69. 2026-08-22 07:34 UTCEG score recompute
  70. 2026-08-22 07:34 UTCGHSA enrichment
  71. 2026-08-21 23:49 UTCEPSS rescore
  72. 2026-08-21 05:31 UTCEG score recompute
  73. 2026-08-21 05:31 UTCGHSA enrichment
  74. 2026-08-20 22:55 UTCEPSS rescore
  75. 2026-08-20 03:27 UTCEG score recompute

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 on August 3, 2026, with the most recent update on September 16, 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 0.3% probability of exploitation in the next 30 days (19th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-49131?
CVE-2026-49131 has a CVSS base score of 5.4 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-49131?
An upstream fix for CVE-2026-49131 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-49131 are linked in the Vendor Advisories panel on this page.

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