CVE-2020-36846

CRITICALNVD 9.89.8
EchelonGraph scoreMEDIUM confidence

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

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2025-05-30. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
Trending — 3 sources updated this week

Also known asEUVD-2025-16444 (ENISA EUVD) · GHSA-44qx-v2f9-7rq9 (GitHub Security Advisories)Source: ENISA EUVD

9.8EG
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).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A buffer overflow, as described in CVE-2020-8927, exists in the embedded Brotli library.  Versions of IO::Compress::Brotli prior to 0.007 included a version of the brotli library prior to version 1.0.8, where an attacker controlling the input length of a "one-shot" decompression request to a script can trigger a crash, which happens when copying over chunks of data larger than 2 GiB. It is recommended to update your IO::Compress::Brotli module to 0.007 or later. If one cannot update, we recommend to use the "streaming" API as opposed to the "one-shot" API, and impose chunk size limits.

CVSS v3
9.8
EG Score
9.8CRITICALmedium confidence
EG Risk
59
EG Risk 59/100

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)
Severity98% × 45%
Impact severity (EG Severity): CVSS 9.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.7% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
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 none (CISA Vulnrichment) · Automatable yes (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
0.7%
EPSS %ILE
51st
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 (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.

EG Severity
9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.7% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-01). 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: 3 days if the affected system is publicly exposed; 60 days 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 or medium mission impact; Attend at high (mission-essential systems).

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

Exploitation none (CISA Vulnrichment) · Automatable yes (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)3 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

May 30, 2025

Last Modified

April 15, 2026

Advisory Details (4)

Auto-updated Oct 8, 2026
Patch available. Sources: github, github_commit, github_pr.
Web page

perl-IO-Compress-Brotli/Changes at 8b44c83b23bb4658179e1494af4b725a1bc476bc · timlegge/perl-IO-Compress-Brotli · GitHub

https://github.com/timlegge/perl-IO-Compress-Brotli/blob/8b44c83b23bb4658179e1494af4b725a1bc476bc/Changes#L52
GitHub pull request Patch Available

Update

Patch available: google/brotli v1.0.8 (PR #826 merged 2020-08-26)

https://github.com/google/brotli/pull/826
GitHub commit Patch Available

commit 223d80cfbec8 (google/brotli)

Patch available: google/brotli v1.0.8 (contains commit 223d80cfbec8)

https://github.com/google/brotli/commit/223d80cfbec8fd346e32906c732c8ede21f0cea6
GitHub advisoryMentions a patch (unverified)

Integer overflow in the bundled Brotli C library · CVE-2020-8927 · GitHub Advisory Database · GitHub

https://github.com/advisories/GHSA-5v8v-66v8-mwm7

Affected Packages

(4 across 3 ecosystems)
crates.io(2)
PackageVulnerable rangeFix by version rangeDependents
brotli-sys—
  • 0.0.0-0 on: no fix on record
—
compu-brotli-sys—
  • 0.0.0-0 up to 1.0.9: fixed in 1.0.9
—
Go(1)
PackageVulnerable rangeFix by version rangeDependents
github.com/google/brotli—
  • every version on: no fix on record
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
brotli0.5.2 ... 1.0.7 (6 versions)
  • every version up to 1.0.8: fixed in 1.0.8
—

Data Freshness Timeline

(refreshed 22× in last 7d / 76× 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 99 of 274 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. 1 repeat row among the latest 100 is merged into the row it repeats. The 175 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 21:50 UTCEG score recompute
  2. 2026-11-01 21:50 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-11-01 16:29 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  4. 2026-10-31 23:46 UTCEG score recompute
  5. 2026-10-31 23:46 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-10-31 16:28 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  7. 2026-10-31 01:43 UTCEG score recompute
  8. 2026-10-31 01:42 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-30 16:29 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  10. 2026-10-30 03:38 UTCEG score recompute
  11. 2026-10-30 03:38 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-10-29 16:28 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  13. 2026-10-29 05:34 UTCEG score recompute
  14. 2026-10-29 05:34 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-10-28 16:28 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  16. 2026-10-28 07:30 UTCEG score recompute
  17. 2026-10-28 07:30 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-10-27 16:28 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  19. 2026-10-27 09:26 UTCEG score recompute
  20. 2026-10-27 09:26 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-26 16:27 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  22. 2026-10-26 11:15 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  23. 2026-10-25 18:42 UTCEG score recompute
  24. 2026-10-25 16:28 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  25. 2026-10-25 13:12 UTCEG score recompute
Show 74 more
  1. 2026-10-25 13:12 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  2. 2026-10-24 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  3. 2026-10-24 15:08 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-10-23 17:04 UTCEG score recompute
  5. 2026-10-23 17:04 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-10-23 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  7. 2026-10-22 18:59 UTCEG score recompute
  8. 2026-10-22 18:59 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-22 16:29 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  10. 2026-10-21 20:55 UTCEG score recompute
  11. 2026-10-21 20:55 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-10-21 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  13. 2026-10-20 22:51 UTCEG score recompute
  14. 2026-10-20 22:51 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-10-20 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  16. 2026-10-20 00:35 UTCEG score recompute
  17. 2026-10-20 00:35 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-10-19 16:27 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  19. 2026-10-18 23:32 UTCEG score recompute
  20. 2026-10-18 23:32 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-10-18 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  22. 2026-10-18 09:22 UTCEG score recompute
  23. 2026-10-18 01:25 UTCEG score recompute
  24. 2026-10-18 01:25 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-10-17 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  26. 2026-10-17 02:59 UTCEG score recompute
  27. 2026-10-17 02:59 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  28. 2026-10-16 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  29. 2026-10-16 04:53 UTCEG score recompute
  30. 2026-10-16 04:53 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  31. 2026-10-15 16:27 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  32. 2026-10-15 03:18 UTCEG score recompute
  33. 2026-10-15 03:18 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  34. 2026-10-14 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  35. 2026-10-13 23:32 UTCEG score recompute
  36. 2026-10-13 23:32 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  37. 2026-10-13 16:28 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  38. 2026-10-12 19:36 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  39. 2026-10-12 19:35 UTCEG score recompute
  40. 2026-10-12 16:29 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  41. 2026-10-11 23:59 UTCEG score recompute
  42. 2026-10-11 13:43 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  43. 2026-10-10 19:56 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  44. 2026-10-09 20:04 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  45. 2026-10-08 16:38 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  46. 2026-10-07 23:44 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  47. 2026-10-06 15:13 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  48. 2026-10-05 17:39 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  49. 2026-10-04 23:18 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  50. 2026-10-03 14:22 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  51. 2026-10-03 08:09 UTCOSV refresh
  52. 2026-09-30 15:19 UTCEG score recompute
  53. 2026-09-30 14:59 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  54. 2026-09-29 15:14 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  55. 2026-09-27 13:41 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  56. 2026-09-26 15:54 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  57. 2026-09-24 14:00 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  58. 2026-09-22 14:43 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  59. 2026-09-21 20:28 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  60. 2026-09-20 20:11 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  61. 2026-09-19 15:37 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  62. 2026-09-18 19:23 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  63. 2026-09-17 19:22 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  64. 2026-09-16 14:04 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  65. 2026-09-15 03:06 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  66. 2026-09-14 03:50 UTCOSV refresh
  67. 2026-09-13 16:43 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  68. 2026-09-12 14:57 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  69. 2026-09-11 09:32 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  70. 2026-09-08 21:56 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  71. 2026-09-07 15:57 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  72. 2026-09-06 13:44 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  73. 2026-09-05 15:24 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  74. 2026-09-04 13:57 UTCEPSS rescoreEPSS 0.6% · 48th percentile

Frequently asked(5)

What is CVE-2020-36846?
CVE-2020-36846 is a critical-severity vulnerability; its CVE record was published on May 30, 2025. A buffer overflow, as described in CVE-2020-8927, exists in the embedded Brotli library. Versions of IO::Compress::Brotli prior to 0.007 included a version of the brotli library prior to version 1.0.8, where an attacker controlling the input length of a "one-shot" decompression request to a script…
When was the CVE record for CVE-2020-36846 published?
The CVE record for CVE-2020-36846 was published on May 30, 2025. 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 April 15, 2026; the record at its source may have been updated since.
Is CVE-2020-36846 actively exploited?
CVE-2020-36846 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (51st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2020-36846?
CVE-2020-36846 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2020-36846?
A fix for CVE-2020-36846 is available: update to the fixed version the vendor names in its advisory.

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