CVE-2026-78966

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreMEDIUM confidence

Score 4.3 from GitHub Security Advisory published 2026-08-25. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 4.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 4 sources updated this week
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 4.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Externally controlled reference in QUIC in Google Chrome prior to 152.0.7977.65 allowed a remote attacker to bypass web origin policy via a crafted HTML page. (Chromium security severity: Medium)

CVSS v3
4.3
Vendor severity
MEDIUMper Google (Chromium)Vendor's own band, not a CVSS rating — advisory text: (Chromium security severity: Medium)
EG Score
4.3MEDIUMmedium confidence
EG Risk
19
EG Risk 19/100CISA 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
Severity43% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
23rd
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

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 25, 2026

Last Modified

August 28, 2026

Advisory Details (2)

Auto-updated Aug 27, 2026
Patch available.
generic

Chromium

https://issues.chromium.org/issues/497637694
generic

Chrome Releases: Stable Channel Update for Desktop

https://chromereleases.googleblog.com/2026/08/stable-channel-update-for-desktop_0256176589.html

Vendor Advisories for CVE-2026-78966(2)

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

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
chromium113.0.5672.126-1 ... 152.0.7977.64-1 (412 versions)
  • every version up to 152.0.7977.75-1~deb12u1: fixed in 152.0.7977.75-1~deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
chromium138.0.7204.183-1 ... 152.0.7977.75-1~deb12u1 (178 versions)
  • every version up to 152.0.7977.75-1~deb13u1: fixed in 152.0.7977.75-1~deb13u1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
chromium138.0.7204.183-1 ... 151.0.7922.71-1~deb13u1 (176 versions)
  • every version up to 152.0.7977.64-1: fixed in 152.0.7977.64-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 25× in last 7d / 108× 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 170 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-78966?
CVE-2026-78966 is a medium vulnerability published on August 25, 2026. Externally controlled reference in QUIC in Google Chrome prior to 152.0.7977.65 allowed a remote attacker to bypass web origin policy via a crafted HTML page. (Chromium security severity: Medium)
When was CVE-2026-78966 disclosed?
CVE-2026-78966 was first published on August 25, 2026, with the most recent update on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-78966 actively exploited?
CVE-2026-78966 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (23rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-78966?
CVE-2026-78966 has a CVSS v3.1 base score of 4.3 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-78966?
A fix for CVE-2026-78966 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-78966 are linked in the Vendor Advisories panel on this page.

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