CVE-2026-82820

MEDIUMPre-NVD 4.34.3
EchelonGraph scoreMEDIUM confidence

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

Score 4.3 from GitHub Security Advisory (severity: LOW) published 2026-08-31. A secondary CVSS source baseline 4.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Elevated

Also known asEUVD-2026-68721 (ENISA EUVD) · GHSA-83mv-5j75-x432 (GitHub Security Advisories)Source: ENISA EUVD

4.3EG
EchelonGraph verdictPlan mitigationThe upstream fix is not in a release yet: until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high, then apply it (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: 0.6%CVSS: 4.3Exploit: No code on recordExposed services: Not assessed

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

A vulnerability was found in FLVMeta up to 1.2.2. Affected is the function amf_string_new of the file src/amf.c of the component AMF String Processing. The manipulation of the argument length results in heap-based buffer overflow. The attack can be launched remotely. The exploit has been made public and could be used. The patch is identified as f412a33b9a84c2d1a9dee145a868feddbf64879e. A patch should be applied to remediate this issue. The project maintainer doubts the security impact: "While I acknowledged the bugs and provided fixes, I have yet to see any way to exploit these alleged vulnerabilities."

CVSS v3
4.3
EG Score
4.3MEDIUMmedium confidence
EG Risk
50
EG Risk 50/100

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)
Severity43% × 45%
Impact severity (EG Severity): CVSS 4.3 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.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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: An upstream fix is merged but not yet in a tagged release. Until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high, then apply it.
EPSS PROB
0.6%
EPSS %ILE
50th
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 (4.3): severity, escalated by confirmed exploitation. This CVE's 4.3 is its impact severity (EG Severity), not escalated.

EG Severity
4.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.6% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). 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; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says.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 or medium mission impact; Attend at high (mission-essential systems).

An upstream fix is merged but not yet in a tagged release. Until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high, then apply it.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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; 60 days if it is not.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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 31, 2026

Last Modified

September 1, 2026

Advisory Details (3)

Auto-updated Aug 31, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
GitHub commit

commit f412a33b9a84 (noirotm/flvmeta)

Fix landed in noirotm/flvmeta commit f412a33b9a84 — awaiting tagged release

https://github.com/noirotm/flvmeta/commit/f412a33b9a84c2d1a9dee145a868feddbf64879e
Web page

Poc/flvmeta_heap_buffer_overflow at main · raind20001020/Poc · GitHub

https://github.com/raind20001020/Poc/blob/main/flvmeta_heap_buffer_overflow
Web page

Vuln:flvmeta heap-buffer-overflow · Issue #27 · noirotm/flvmeta · GitHub

https://github.com/noirotm/flvmeta/issues/27

Vendor Advisories for CVE-2026-82820(1)

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
flvmeta1.2.1-1, 1.2.2-1, 1.2.2-2, 1.2.2-2~exp1
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
flvmeta1.2.2-1, 1.2.2-2, 1.2.2-2~exp1
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
flvmeta1.2.2-1, 1.2.2-2, 1.2.2-2~exp1
  • every version on: no fix on record
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 52× 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 141 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 41 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 0.6% · 50th percentile
  2. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  3. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  4. 2026-10-30 01:25 UTCOSV refresh
  5. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  6. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  7. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  8. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  10. 2026-10-25 13:57 UTCEG score recompute
  11. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  12. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  14. 2026-10-22 13:42 UTCEG score recompute
  15. 2026-10-22 13:42 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  16. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  17. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  18. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  19. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  20. 2026-10-18 03:08 UTCEG score recompute
  21. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  22. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  23. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  24. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  25. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.6% · 48th percentile
Show 75 more
  1. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  2. 2026-10-12 14:55 UTCEG score recompute
  3. 2026-10-11 19:19 UTCEG score recompute
  4. 2026-10-11 16:36 UTCEG score recompute
  5. 2026-10-11 13:53 UTCEG score recompute
  6. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  7. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  8. 2026-10-10 03:41 UTCEG score recompute
  9. 2026-10-10 03:41 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  11. 2026-10-09 02:20 UTCEG score recompute
  12. 2026-10-09 02:20 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  13. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  14. 2026-10-08 00:30 UTCEG score recompute
  15. 2026-10-08 00:30 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  16. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  17. 2026-10-06 18:09 UTCEG score recompute
  18. 2026-10-06 18:09 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  19. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  20. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  21. 2026-10-05 17:10 UTCEG score recompute
  22. 2026-10-05 17:10 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  23. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  24. 2026-10-04 16:12 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  25. 2026-10-03 15:12 UTCEG score recompute
  26. 2026-10-03 15:12 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  27. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  28. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  29. 2026-10-02 14:09 UTCEG score recompute
  30. 2026-10-02 14:09 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  31. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  32. 2026-10-01 13:08 UTCEG score recompute
  33. 2026-10-01 13:07 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  34. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  35. 2026-09-30 12:09 UTCEG score recompute
  36. 2026-09-30 12:09 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  37. 2026-09-29 11:08 UTCEG score recompute
  38. 2026-09-29 11:08 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  39. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  40. 2026-09-28 09:14 UTCEG score recompute
  41. 2026-09-28 09:14 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  42. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  43. 2026-09-27 08:16 UTCEG score recompute
  44. 2026-09-27 08:16 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  45. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  46. 2026-09-26 07:11 UTCEG score recompute
  47. 2026-09-26 07:11 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  48. 2026-09-24 18:39 UTCEG score recompute
  49. 2026-09-24 18:39 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  50. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  51. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  52. 2026-09-23 17:17 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  53. 2026-09-22 16:15 UTCEG score recompute
  54. 2026-09-22 16:15 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  55. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  56. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  57. 2026-09-21 15:08 UTCEG score recompute
  58. 2026-09-21 15:08 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  59. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  60. 2026-09-20 14:04 UTCEG score recompute
  61. 2026-09-20 14:04 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  62. 2026-09-19 13:06 UTCEG score recompute
  63. 2026-09-19 13:06 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  64. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  65. 2026-09-18 12:08 UTCEG score recompute
  66. 2026-09-18 12:08 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  67. 2026-09-17 11:09 UTCEG score recompute
  68. 2026-09-17 11:09 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  69. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  70. 2026-09-16 10:11 UTCEG score recompute
  71. 2026-09-16 10:11 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  72. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  73. 2026-09-15 09:12 UTCEG score recompute
  74. 2026-09-15 09:12 UTCGHSA enrichmentGHSA-83mv-5j75-x432 · GitHub severity LOW · GitHub CVSS 4.3
  75. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.4% · 29th percentile

Frequently asked(5)

What is CVE-2026-82820?
CVE-2026-82820 is a medium-severity vulnerability; its CVE record was published on August 31, 2026. A vulnerability was found in FLVMeta up to 1.2.2. Affected is the function amf_string_new of the file src/amf.c of the component AMF String Processing. The manipulation of the argument length results in heap-based buffer overflow. The attack can be launched remotely. The exploit has been made…
When was the CVE record for CVE-2026-82820 published?
The CVE record for CVE-2026-82820 was published on August 31, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 1, 2026; the record at its source may have been updated since.
Is CVE-2026-82820 actively exploited?
CVE-2026-82820 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (50th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-82820?
CVE-2026-82820 has a CVSS base score of 4.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-82820?
An upstream fix for CVE-2026-82820 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-2026-82820 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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