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

Also known asEUVD-2025-16444 (ENISA EUVD) · GHSA-44qx-v2f9-7rq9 (GitHub Security Advisories) · GO-2025-3726 (OSV.dev) · PYSEC-2020-29 (OSV.dev) · RUSTSEC-2021-0131 (OSV.dev) · RUSTSEC-2021-0132 (OSV.dev)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
52nd
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 2026-11-12). 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 14× in last 7d / 63× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 310 rows 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 210 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 22:56 UTCEchelonGraph re-scored
  2. 2026-11-12 22:56 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  3. 2026-11-12 16:29 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  4. 2026-11-12 00:52 UTCEchelonGraph re-scored
  5. 2026-11-12 00:52 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-11-11 16:31 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  7. 2026-11-11 02:49 UTCEchelonGraph re-scored
  8. 2026-11-11 02:49 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-11-10 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  10. 2026-11-10 04:31 UTCEchelonGraph re-scored
  11. 2026-11-10 04:31 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  12. 2026-11-09 16:28 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  13. 2026-11-09 06:27 UTCEchelonGraph re-scored
  14. 2026-11-09 06:27 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  15. 2026-11-08 16:32 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  16. 2026-11-08 08:23 UTCEchelonGraph re-scored
  17. 2026-11-08 08:23 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  18. 2026-11-07 16:33 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  19. 2026-11-07 10:20 UTCEchelonGraph re-scored
  20. 2026-11-07 10:20 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  21. 2026-11-06 16:29 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  22. 2026-11-06 12:12 UTCEchelonGraph re-scored
  23. 2026-11-06 12:12 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  24. 2026-11-05 16:30 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  25. 2026-11-05 14:08 UTCEchelonGraph re-scored
Show 75 more
  1. 2026-11-05 14:08 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  2. 2026-11-04 16:29 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  3. 2026-11-04 16:04 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  4. 2026-11-03 17:59 UTCEchelonGraph re-scored
  5. 2026-11-03 17:59 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  6. 2026-11-03 16:36 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  7. 2026-11-03 12:55 UTCOSV refresh
  8. 2026-11-02 19:55 UTCEchelonGraph re-scored
  9. 2026-11-02 19:55 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  10. 2026-11-02 16:36 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  11. 2026-11-01 21:50 UTCEchelonGraph re-scored
  12. 2026-11-01 21:50 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-11-01 16:29 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  14. 2026-10-31 23:46 UTCEchelonGraph re-scored
  15. 2026-10-31 23:46 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  16. 2026-10-31 16:28 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  17. 2026-10-31 01:43 UTCEchelonGraph re-scored
  18. 2026-10-31 01:42 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  19. 2026-10-30 16:29 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  20. 2026-10-30 03:38 UTCEchelonGraph re-scored
  21. 2026-10-30 03:38 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  22. 2026-10-29 16:28 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  23. 2026-10-29 05:34 UTCEchelonGraph re-scored
  24. 2026-10-29 05:34 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  25. 2026-10-28 16:28 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  26. 2026-10-28 07:30 UTCEchelonGraph re-scored
  27. 2026-10-28 07:30 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  28. 2026-10-27 16:28 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  29. 2026-10-27 09:26 UTCEchelonGraph re-scored
  30. 2026-10-27 09:26 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  31. 2026-10-26 16:27 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  32. 2026-10-26 11:15 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  33. 2026-10-25 18:42 UTCEchelonGraph re-scored
  34. 2026-10-25 16:28 UTCEPSS rescoreEPSS 0.6% · 50th percentile
  35. 2026-10-25 13:12 UTCEchelonGraph re-scored
  36. 2026-10-25 13:12 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  37. 2026-10-24 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  38. 2026-10-24 15:08 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  39. 2026-10-23 17:04 UTCEchelonGraph re-scored
  40. 2026-10-23 17:04 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  41. 2026-10-23 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  42. 2026-10-22 18:59 UTCEchelonGraph re-scored
  43. 2026-10-22 18:59 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  44. 2026-10-22 16:29 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  45. 2026-10-21 20:55 UTCEchelonGraph re-scored
  46. 2026-10-21 20:55 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  47. 2026-10-21 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  48. 2026-10-20 22:51 UTCEchelonGraph re-scored
  49. 2026-10-20 22:51 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  50. 2026-10-20 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  51. 2026-10-20 00:35 UTCEchelonGraph re-scored
  52. 2026-10-20 00:35 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  53. 2026-10-19 16:27 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  54. 2026-10-18 23:32 UTCEchelonGraph re-scored
  55. 2026-10-18 23:32 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  56. 2026-10-18 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  57. 2026-10-18 09:22 UTCEchelonGraph re-scored
  58. 2026-10-18 01:25 UTCEchelonGraph re-scored
  59. 2026-10-18 01:25 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  60. 2026-10-17 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  61. 2026-10-17 02:59 UTCEchelonGraph re-scored
  62. 2026-10-17 02:59 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  63. 2026-10-16 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  64. 2026-10-16 04:53 UTCEchelonGraph re-scored
  65. 2026-10-16 04:53 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  66. 2026-10-15 16:27 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  67. 2026-10-15 03:18 UTCEchelonGraph re-scored
  68. 2026-10-15 03:18 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  69. 2026-10-14 16:28 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  70. 2026-10-13 23:32 UTCEchelonGraph re-scored
  71. 2026-10-13 23:32 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  72. 2026-10-13 16:28 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  73. 2026-10-12 19:36 UTCGHSA enrichmentGHSA-44qx-v2f9-7rq9 · GitHub severity CRITICAL · GitHub CVSS 9.8
  74. 2026-10-12 19:35 UTCEchelonGraph re-scored
  75. 2026-10-12 16:29 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 (52nd 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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