CVE-2026-86320

HIGHPre-NVD 7.87.8
EchelonGraph scoreMEDIUM confidence

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

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-17. A secondary CVSS source baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — Patch released this weekElevated

Also known asEUVD-2026-81387 (ENISA EUVD) · GHSA-rvpr-5p35-6vf8 (GitHub Security Advisories)Source: ENISA EUVD

7.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 7.8Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

A flaw was found in flatpak-builder where Git hooks are not disabled when applying patch sources with use-git-am: true. An attacker who can provide a malicious source containing a Git post-applypatch hook can cause the hook to execute on the host during the build process, resulting in arbitrary code execution with the privileges of the user running flatpak-builder.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
51
EG Risk 51/100

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)
Severity78% × 45%
Impact severity (EG Severity): CVSS 7.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.3%
EPSS %ILE
22nd
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 (7.8): severity, escalated by confirmed exploitation. This CVE's 7.8 is its impact severity (EG Severity), not escalated.

EG Severity
7.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.3% 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, Track* at medium and Attend at high mission impact.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, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (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.

The score's inputs: 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

September 17, 2026

Last Modified

October 30, 2026

Advisory Details (3)

Auto-updated Sep 17, 2026
Patch available. Sources: redhat, github.
GitHub advisoryMentions a patch (unverified)

CVE-2026-86320: Arbitrary host code execution via git hooks during module source extraction · Advisory · flatpak/flatpak-builder · GitHub

https://github.com/flatpak/flatpak-builder/security/advisories/GHSA-j5p8-jgjc-f3xv
Red Hat

2471023 – (CVE-2026-86320) CVE-2026-86320 flatpak-builder: Host code execution via `git am` hook execution in patch source extraction (`use-git-am`)

https://bugzilla.redhat.com/show_bug.cgi?id=2471023
Red HatMentions a patch (unverified)

CVE-2026-86320 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-86320

Patch Availability(9)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatflatpak-builder-0:1.0.9-4.el8_62026-10-27redhat
redhatflatpak-builder-0:1.0.14-3.el8_82026-10-21redhat
redhatflatpak-builder-0:1.2.3-1.el9_6.12026-10-19redhat
redhatflatpak-builder-0:1.4.4-1.el10_0.12026-10-19redhat
redhatflatpak-builder-0:1.2.2-2.el9_22026-10-19redhat
redhatflatpak-builder-0:1.2.3-2.el9_42026-10-19redhat
redhatflatpak-builder-0:1.4.4-1.el10_2.12026-10-12redhat
redhatflatpak-builder-0:1.2.3-2.el8_102026-10-12redhat
redhatflatpak-builder-0:1.2.3-1.el9_8.12026-10-12redhat

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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
flatpak-builder1.2.3-1 ... 1.4.9-1 (21 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
flatpak-builder1.4.10-1 ... 1.4.9-1 (11 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
flatpak-builder1.4.10-1 ... 1.4.9-1 (8 versions)
  • every version up to 1.4.11-1: fixed in 1.4.11-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 18× in last 7d / 96× 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 167 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 67 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  4. 2026-10-30 01:26 UTCEG score recompute
  5. 2026-10-30 01:26 UTCVendor advisory
  6. 2026-10-30 01:26 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  7. 2026-10-30 00:46 UTCEG score recompute
  8. 2026-10-30 00:46 UTCVendor advisory
  9. 2026-10-30 00:46 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  10. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  11. 2026-10-28 19:28 UTCEG score recompute
  12. 2026-10-28 19:28 UTCVendor advisory
  13. 2026-10-28 19:28 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  14. 2026-10-28 18:53 UTCEG score recompute
  15. 2026-10-28 18:53 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  16. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  17. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  18. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  19. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  20. 2026-10-25 13:54 UTCEG score recompute
  21. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  22. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  23. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  24. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  25. 2026-10-21 12:26 UTCEG score recompute
Show 75 more
  1. 2026-10-21 12:26 UTCVendor advisory
  2. 2026-10-21 12:26 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  3. 2026-10-21 11:26 UTCEG score recompute
  4. 2026-10-21 11:26 UTCVendor advisory
  5. 2026-10-21 11:26 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  6. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 14th percentile
  7. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  8. 2026-10-19 13:26 UTCVendor advisory
  9. 2026-10-19 13:26 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  10. 2026-10-19 12:27 UTCEG score recompute
  11. 2026-10-19 12:27 UTCVendor advisory
  12. 2026-10-19 12:27 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  13. 2026-10-19 12:04 UTCEG score recompute
  14. 2026-10-19 12:04 UTCVendor advisory
  15. 2026-10-19 12:04 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  16. 2026-10-18 03:05 UTCEG score recompute
  17. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  18. 2026-10-17 09:34 UTCEG score recompute
  19. 2026-10-17 09:34 UTCVendor advisory
  20. 2026-10-17 09:34 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  21. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  22. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  23. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  24. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  25. 2026-10-12 21:26 UTCEG score recompute
  26. 2026-10-12 21:26 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  27. 2026-10-12 20:26 UTCEG score recompute
  28. 2026-10-12 20:26 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  29. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  30. 2026-10-12 14:51 UTCEG score recompute
  31. 2026-10-12 03:28 UTCEG score recompute
  32. 2026-10-12 03:27 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  33. 2026-10-12 02:51 UTCEG score recompute
  34. 2026-10-12 02:50 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  35. 2026-10-11 19:17 UTCEG score recompute
  36. 2026-10-11 16:48 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  37. 2026-10-11 16:33 UTCEG score recompute
  38. 2026-10-11 13:51 UTCEG score recompute
  39. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  40. 2026-10-11 05:26 UTCEG score recompute
  41. 2026-10-11 05:26 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  42. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  43. 2026-10-10 18:04 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  44. 2026-10-10 06:41 UTCEG score recompute
  45. 2026-10-10 06:41 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  46. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  47. 2026-10-09 19:15 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  48. 2026-10-09 07:53 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  49. 2026-10-08 20:31 UTCEG score recompute
  50. 2026-10-08 20:30 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  51. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  52. 2026-10-08 07:42 UTCEG score recompute
  53. 2026-10-08 07:42 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  54. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  55. 2026-10-07 20:19 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  56. 2026-10-07 08:57 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  57. 2026-10-06 21:34 UTCEG score recompute
  58. 2026-10-06 21:34 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  59. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  60. 2026-10-06 10:10 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  61. 2026-10-05 22:26 UTCEG score recompute
  62. 2026-10-05 22:26 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  63. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  64. 2026-10-05 10:58 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  65. 2026-10-04 23:31 UTCEG score recompute
  66. 2026-10-04 23:31 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  67. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  68. 2026-10-04 12:08 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  69. 2026-10-04 00:46 UTCEG score recompute
  70. 2026-10-04 00:46 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  71. 2026-10-03 13:24 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  72. 2026-10-03 02:02 UTCEG score recompute
  73. 2026-10-03 02:02 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8
  74. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  75. 2026-10-02 14:40 UTCGHSA enrichmentGHSA-rvpr-5p35-6vf8 · GitHub severity HIGH · GitHub CVSS 7.8

Frequently asked(5)

What is CVE-2026-86320?
CVE-2026-86320 is a high-severity vulnerability; its CVE record was published on September 17, 2026. A flaw was found in flatpak-builder where Git hooks are not disabled when applying patch sources with use-git-am: true. An attacker who can provide a malicious source containing a Git post-applypatch hook can cause the hook to execute on the host during the build process, resulting in arbitrary…
When was CVE-2026-86320 made public?
CVE-2026-86320 was made public on August 13, 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 September 17, 2026. EchelonGraph's copy of the record carries a last-modified date of October 30, 2026; the record at its source may have been updated since.
Is CVE-2026-86320 actively exploited?
CVE-2026-86320 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (22nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-86320?
CVE-2026-86320 has a CVSS base score of 7.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-86320?
A fix for CVE-2026-86320 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-86320 are linked in the Vendor Advisories panel on this page.

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