CVE-2026-78376

HIGHPre-NVD 8.88.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-08-24. A secondary CVSS source baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this week

Also known asEUVD-2026-64858 (ENISA EUVD) · GHSA-qcc7-6r53-qpph (GitHub Security Advisories)Source: ENISA EUVD

8.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A flaw was found in WebKitGTK. Processing malicious web content can cause a use-after-free issue due to improper memory handling and result in memory corruption.

CVSS v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
40
EG Risk 40/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.3% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
31st
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.

EG Severity
8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

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

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

August 24, 2026

Last Modified

October 26, 2026

Advisory Details (2)

Auto-updated Aug 24, 2026
Patch available. Sources: redhat.
Red Hat

2521858 – (CVE-2026-78376) CVE-2026-78376 webkitgtk: use-after-free of JSCValue function parameters

https://bugzilla.redhat.com/show_bug.cgi?id=2521858
Red HatMentions a patch (unverified)

CVE-2026-78376 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 7, the following packages require WebKitGTK4: evolution-data-server, glade, gnome-boxes, gnome-initia

https://access.redhat.com/security/cve/CVE-2026-78376

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatwebkit2gtk3-0:2.54.0-1.el8_102026-09-30redhat
redhatwebkit2gtk3-0:2.54.0-1.el9_82026-09-21redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(6 across 3 ecosystems)
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk2.40.1-1 ... 2.54.0-1~exp1 (169 versions)
  • every version on: no fix on record
—
wpewebkit2.38.6-1 ... 2.54.0-2 (56 versions)
  • every version on: no fix on record
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk2.48.3-1 ... 2.53.92-1 (59 versions)
  • every version up to 2.54.0-1~deb13u1: fixed in 2.54.0-1~deb13u1
—
wpewebkit2.48.3-1 ... 2.54.0-2 (22 versions)
  • every version on: no fix on record
—
Debian:14(2)
PackageVulnerable rangeFix by version rangeDependents
webkit2gtk2.48.3-1 ... 2.54.0-1~exp1 (62 versions)
  • every version on: no fix on record
—
wpewebkit2.48.3-1 ... 2.52.6-1 (20 versions)
  • every version up to 2.54.0-1: fixed in 2.54.0-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 17× in last 7d / 105× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 251 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 151 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  2. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  3. 2026-10-26 14:38 UTCEG score recompute
  4. 2026-10-26 14:38 UTCVendor advisory
  5. 2026-10-26 14:38 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  6. 2026-10-26 14:03 UTCEG score recompute
  7. 2026-10-26 14:03 UTCVendor advisory
  8. 2026-10-26 14:03 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  10. 2026-10-25 14:00 UTCEG score recompute
  11. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  12. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  14. 2026-10-21 20:12 UTCEG score recompute
  15. 2026-10-21 20:12 UTCVendor advisory
  16. 2026-10-21 20:12 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  17. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  18. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  19. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  20. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  21. 2026-10-18 03:11 UTCEG score recompute
  22. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  23. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  24. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  25. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
Show 75 more
  1. 2026-10-14 13:32 UTCEG score recompute
  2. 2026-10-14 13:32 UTCVendor advisory
  3. 2026-10-14 13:32 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  4. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  5. 2026-10-13 06:49 UTCEG score recompute
  6. 2026-10-13 06:49 UTCVendor advisory
  7. 2026-10-13 06:49 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  8. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  9. 2026-10-12 15:36 UTCEG score recompute
  10. 2026-10-11 19:22 UTCEG score recompute
  11. 2026-10-11 16:38 UTCEG score recompute
  12. 2026-10-11 13:57 UTCEG score recompute
  13. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  14. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  15. 2026-10-10 13:00 UTCEG score recompute
  16. 2026-10-10 13:00 UTCVendor advisory
  17. 2026-10-10 13:00 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  18. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  19. 2026-10-09 04:54 UTCEG score recompute
  20. 2026-10-09 04:54 UTCVendor advisory
  21. 2026-10-09 04:54 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  22. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  23. 2026-10-08 04:02 UTCEG score recompute
  24. 2026-10-08 04:02 UTCVendor advisory
  25. 2026-10-08 04:02 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  26. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  27. 2026-10-07 05:42 UTCVendor advisory
  28. 2026-10-07 05:42 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  29. 2026-10-06 16:40 UTCEG score recompute
  30. 2026-10-06 16:40 UTCVendor advisory
  31. 2026-10-06 16:40 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  32. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  33. 2026-10-06 02:52 UTCEG score recompute
  34. 2026-10-06 02:52 UTCVendor advisory
  35. 2026-10-06 02:52 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  36. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  37. 2026-10-05 09:44 UTCEG score recompute
  38. 2026-10-05 09:44 UTCVendor advisory
  39. 2026-10-05 09:44 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  40. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  41. 2026-10-04 20:43 UTCVendor advisory
  42. 2026-10-04 20:43 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  43. 2026-10-04 06:17 UTCVendor advisory
  44. 2026-10-04 06:17 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  45. 2026-10-03 17:16 UTCEG score recompute
  46. 2026-10-03 17:16 UTCVendor advisory
  47. 2026-10-03 17:15 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  48. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  49. 2026-10-03 04:08 UTCEG score recompute
  50. 2026-10-03 04:08 UTCVendor advisory
  51. 2026-10-03 04:08 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  52. 2026-10-02 14:49 UTCVendor advisory
  53. 2026-10-02 14:49 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  54. 2026-10-02 01:38 UTCEG score recompute
  55. 2026-10-02 01:38 UTCVendor advisory
  56. 2026-10-02 01:38 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  57. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  58. 2026-10-01 12:34 UTCVendor advisory
  59. 2026-10-01 12:34 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  60. 2026-09-30 23:33 UTCEG score recompute
  61. 2026-09-30 23:33 UTCVendor advisory
  62. 2026-09-30 23:33 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  63. 2026-09-30 23:02 UTCEG score recompute
  64. 2026-09-30 23:02 UTCVendor advisory
  65. 2026-09-30 23:01 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  66. 2026-09-30 20:19 UTCEG score recompute
  67. 2026-09-30 20:19 UTCVendor advisory
  68. 2026-09-30 20:19 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  69. 2026-09-30 07:15 UTCEG score recompute
  70. 2026-09-30 07:15 UTCVendor advisory
  71. 2026-09-30 07:15 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  72. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  73. 2026-09-29 15:15 UTCVendor advisory
  74. 2026-09-29 15:15 UTCGHSA enrichmentGHSA-qcc7-6r53-qpph · GitHub severity HIGH · GitHub CVSS 8.8
  75. 2026-09-28 21:33 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-78376?
CVE-2026-78376 is a high-severity vulnerability; its CVE record was published on August 24, 2026. A flaw was found in WebKitGTK. Processing malicious web content can cause a use-after-free issue due to improper memory handling and result in memory corruption.
When was CVE-2026-78376 made public?
CVE-2026-78376 was made public on August 24, 2026: that is the date its CVE record's CNA, Red Hat, Inc., gives for when the vulnerability was made public. The CVE record itself was published on August 24, 2026. EchelonGraph's copy of the record carries a last-modified date of October 26, 2026; the record at its source may have been updated since.
Is CVE-2026-78376 actively exploited?
CVE-2026-78376 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (31st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-78376?
CVE-2026-78376 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-78376?
A fix for CVE-2026-78376 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-78376 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-78376

Explore →

Is Your Infrastructure Affected by CVE-2026-78376?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.