CVE-2026-64847

MEDIUMPre-NVD 6.86.8
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 6.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (4th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Trending — 4 sources updated this week

Also known asEUVD-2026-83193 (ENISA EUVD) · GHSA-5p39-cfhj-2xmp (GitHub Security Advisories) · PYSEC-2026-4024 (OSV.dev)Source: ENISA EUVD

6.8EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 6.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

AnyIO is a high level asynchronous concurrency and networking framework that works on top of either Trio or asyncio. Prior to 4.14.2, AnyIO starts process-pool workers with standard error connected to a pipe that the parent never drains, even though the documented behavior redirects all three standard streams. Worker code that writes enough attacker-influenced data to sys.stderr can fill the pipe and block before returning the standard-output protocol response, causing the awaiting process-pool call to remain blocked indefinitely. Applications that run untrusted or faulty worker code capable of producing substantial standard-error output are affected. This issue is fixed in version 4.14.2.

CVSS v3
6.8
EG Score
6.8MEDIUMmedium confidence
EG Risk
31
EG Risk 31/100

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)
Severity68% × 45%
Impact severity (EG Severity): CVSS 6.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 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 every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (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: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
4th
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 (6.8): severity, escalated by confirmed exploitation. This CVE's 6.8 is its impact severity (EG Severity), not escalated.

EG Severity
6.8 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). 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 every mission impact level.CISA BOD 26-04: 60 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 every mission impact level.

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

Exploitation none (CISA Vulnrichment) · Automatable no (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)60 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 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

September 18, 2026

Last Modified

September 24, 2026

Advisory Details (4)

Auto-updated Sep 18, 2026
Patch available. Sources: github, github_pr, github_commit, github_release.
GitHub release Patch Available

4.14.2

Patch available: agronholm/anyio 4.14.2

https://github.com/agronholm/anyio/releases/tag/4.14.2
GitHub commit Patch Available

commit f1b7301c8264 (agronholm/anyio)

Patch available: agronholm/anyio 4.14.2 (contains commit f1b7301c8264)

https://github.com/agronholm/anyio/commit/f1b7301c8264b0d2e8d24a5788fd29e93dea4040
GitHub pull request Patch Available

Fixed stderr writes in a worker subprocess causing a deadlock

Patch available: agronholm/anyio 4.14.2 (PR #1207 merged 2026-07-08)

https://github.com/agronholm/anyio/pull/1207
GitHub advisoryMentions a patch (unverified)

AnyIO process-pool workers can block indefinitely on undrained stderr · Advisory · agronholm/anyio · GitHub

Affected: v4.14.2.

https://github.com/agronholm/anyio/security/advisories/GHSA-5p39-cfhj-2xmp

Patch Availability(8)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatrhaiis/vllm-cuda-rhel9:17906217182026-09-30redhat
redhatrhaiis/vllm-rocm-rhel9:17906217132026-09-30redhat
redhatrhaii/vllm-cpu-rhel9:17900757932026-09-23redhat
redhatrhaii/vllm-spyre-rhel9:17900761412026-09-23redhat
redhatrhaii/vllm-cuda-rhel9:17900901312026-09-23redhat
redhatrhaii/vllm-rocm-rhel9:17901096202026-09-23redhat
redhatrhaii/model-opt-cuda-rhel9:17900764982026-09-23redhat
pipanyio @ 4.14.2 (fixes < 4.14.2)—ghsa

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

(4 across 4 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
python-anyio3.6.2-1 ... 4.8.0-3 (24 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
python-anyio4.11.0-1 ... 4.8.0-3 (10 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
python-anyio4.11.0-1 ... 4.8.0-3 (7 versions)
  • every version up to 4.15.1-1: fixed in 4.15.1-1
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
anyio1.0.0 ... 4.9.0 (69 versions)
  • every version up to 4.14.2: fixed in 4.14.2
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 55× 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.

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 87 is merged into the row it repeats.

  1. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  2. 2026-11-01 07:40 UTCGHSA enrichmentGHSA-5p39-cfhj-2xmp · GitHub severity MODERATE
  3. 2026-11-01 07:40 UTCEG score recompute
  4. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  5. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  6. 2026-10-30 08:25 UTCOSV refresh
  7. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  8. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  9. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  10. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  11. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  12. 2026-10-25 14:12 UTCEG score recompute
  13. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  14. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  15. 2026-10-22 19:42 UTCEG score recompute
  16. 2026-10-22 19:42 UTCVendor advisory
  17. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  18. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  19. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  20. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  21. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  22. 2026-10-18 03:22 UTCEG score recompute
  23. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  24. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  25. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 4th percentile
Show 61 more
  1. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  2. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  3. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  4. 2026-10-12 15:47 UTCEG score recompute
  5. 2026-10-11 19:32 UTCEG score recompute
  6. 2026-10-11 17:04 UTCVendor advisory
  7. 2026-10-11 16:47 UTCEG score recompute
  8. 2026-10-11 14:08 UTCEG score recompute
  9. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  10. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  11. 2026-10-10 17:32 UTCEG score recompute
  12. 2026-10-10 17:32 UTCVendor advisory
  13. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  14. 2026-10-09 17:53 UTCVendor advisory
  15. 2026-10-08 17:32 UTCEG score recompute
  16. 2026-10-08 17:32 UTCVendor advisory
  17. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  18. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  19. 2026-10-07 18:00 UTCVendor advisory
  20. 2026-10-06 16:34 UTCEG score recompute
  21. 2026-10-06 16:34 UTCVendor advisory
  22. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  23. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  24. 2026-10-05 16:59 UTCEG score recompute
  25. 2026-10-05 16:59 UTCVendor advisory
  26. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  27. 2026-10-04 17:27 UTCVendor advisory
  28. 2026-10-03 17:56 UTCEG score recompute
  29. 2026-10-03 17:56 UTCVendor advisory
  30. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  31. 2026-10-02 18:22 UTCEG score recompute
  32. 2026-10-02 18:22 UTCVendor advisory
  33. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  34. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  35. 2026-10-01 18:50 UTCVendor advisory
  36. 2026-09-30 18:59 UTCEG score recompute
  37. 2026-09-30 18:59 UTCVendor advisory
  38. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  39. 2026-09-29 19:28 UTCEG score recompute
  40. 2026-09-29 19:28 UTCVendor advisory
  41. 2026-09-28 19:50 UTCEG score recompute
  42. 2026-09-28 19:50 UTCVendor advisory
  43. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  44. 2026-09-27 20:16 UTCEG score recompute
  45. 2026-09-27 20:16 UTCVendor advisory
  46. 2026-09-26 20:44 UTCEG score recompute
  47. 2026-09-26 20:44 UTCVendor advisory
  48. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  49. 2026-09-25 21:11 UTCVendor advisory
  50. 2026-09-24 21:38 UTCVendor advisory
  51. 2026-09-24 15:41 UTCEG score recompute
  52. 2026-09-24 15:41 UTCVendor advisory
  53. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  54. 2026-09-22 16:38 UTCEG score recompute
  55. 2026-09-21 17:06 UTCEG score recompute
  56. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.1% · 2nd percentile
  57. 2026-09-19 18:01 UTCEG score recompute
  58. 2026-09-18 18:27 UTCEG score recompute
  59. 2026-09-18 18:15 UTCEG score recompute
  60. 2026-09-18 17:19 UTCEG score recomputeFirst assessed: 6.8 MEDIUM
  61. 2026-09-18 17:19 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-64847?
CVE-2026-64847 is a medium-severity vulnerability; its CVE record was published on September 18, 2026. AnyIO is a high level asynchronous concurrency and networking framework that works on top of either Trio or asyncio. Prior to 4.14.2, AnyIO starts process-pool workers with standard error connected to a pipe that the parent never drains, even though the documented behavior redirects all three…
When was the CVE record for CVE-2026-64847 published?
The CVE record for CVE-2026-64847 was published on September 18, 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 24, 2026; the record at its source may have been updated since.
Is CVE-2026-64847 actively exploited?
CVE-2026-64847 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (4th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-64847?
CVE-2026-64847 has a CVSS base score of 6.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-64847?
A fix for CVE-2026-64847 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-64847 are linked in the Vendor Advisories panel on this page.

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