CVE-2026-8948

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-05-19. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: None knownExposed: 0

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

Same-origin policy bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
56(Track)
EG Risk 56/100SSVC: 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
Severity91% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
35%
KEV
Not listed

Published

May 19, 2026

Last Modified

July 15, 2026

Advisory Details (3)

Auto-updated Aug 29, 2026
No patch confirmed yet.
generic

Security Vulnerabilities fixed in Thunderbird 151 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-50/
generic

Security Vulnerabilities fixed in Firefox 151 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-46/
generic

2038803 - (CVE-2026-8948) SOP bypass: SW FollowSyntheticRedirect leaks tainting flag, bypasses CORS

https://bugzilla.mozilla.org/show_bug.cgi?id=2038803

Vendor Advisories for CVE-2026-8948(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 92× 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 294 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-8948?
CVE-2026-8948 is a critical vulnerability published on May 19, 2026. Same-origin policy bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
When was CVE-2026-8948 disclosed?
CVE-2026-8948 was first published in the National Vulnerability Database on May 19, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-8948 actively exploited?
CVE-2026-8948 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 64.9% of all scored CVEs.
What is the CVSS score of CVE-2026-8948?
CVE-2026-8948 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-8948?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8948, 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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