AnyIO is a high level asynchronous concurrency and networking framework that works on top of either Trio or asyncio. Prior to 4.14.2, connect_tcp() and TLSStream.wrap() can validate internationalized host names after the standard library converts them with IDNA 2003 instead of IDNA 2008. When a connection to a non-ASCII domain is hijacked or redirected, an attacker can obtain a legitimate certificate for the different ASCII hostname produced by IDNA 2003 and present it to the client, causing the malicious endpoint's certificate to validate. This issue is fixed in version 4.14.2.
CVE-2026-63374
“—” beside the score: it is equal to the CVSS score beside it.
This critical-severity CVE scores 9.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (21st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2026-84522 (ENISA EUVD) · GHSA-82r6-8w77-94w6 (GitHub Security Advisories)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 9.3
- EG Score
- 9.3CRITICALmedium confidence
- EG Risk
- 57EG Risk 57/100
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)Severity93% × 45%Impact severity (EG Severity): CVSS 9.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.3% × 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
- 0.3%
- EPSS %ILE
- 21st
- 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 (9.3): severity, escalated by confirmed exploitation. This CVE's 9.3 is its impact severity (EG Severity), not escalated.
- EG Severity
- 9.3 CRITICALCVSS-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
- 0.3% 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
September 18, 2026
Last Modified
September 28, 2026
Advisory Details (4)
Auto-updated Oct 3, 2026TLSStream IDNA 2003 host name encoding enables potential TLS certificate spoofing · Advisory · agronholm/anyio · GitHub
Affected: v4.14.2.
https://github.com/agronholm/anyio/security/advisories/GHSA-82r6-8w77-94w64.14.2
Patch available: agronholm/anyio 4.14.2
https://github.com/agronholm/anyio/releases/tag/4.14.2Fixed TLSStream.wrap() using IDNA 2003 to encode host names
Patch available: agronholm/anyio 4.14.2 (PR #1208 merged 2026-07-08)
https://github.com/agronholm/anyio/pull/1208commit 68f58915f82d (agronholm/anyio)
Patch available: agronholm/anyio 4.14.2 (contains commit 68f58915f82d)
https://github.com/agronholm/anyio/commit/68f58915f82d9be8109ebbbd8f5d70577d43f2ceVendor Advisories for CVE-2026-63374(14)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:92588Red Hat Product SecurityHigh
Red Hat Security Advisory: Technical preview of the satellite/iop-vmaas-rhel9 container image
- RHSA-2026:92583Red Hat Product SecurityCritical
Red Hat Security Advisory: General availability of the satellite/iop-host-inventory-rhel9 container image
- RHSA-2026:92574Red Hat Product SecurityHigh
Red Hat Security Advisory: Technical preview of the satellite/iop-vmaas-rhel9 container image
- RHSA-2026:92566Red Hat Product SecurityCritical
Red Hat Security Advisory: General availability of the satellite/iop-host-inventory-rhel9 container image
- RHSA-2026:92510Red Hat Product SecurityCritical
Red Hat Security Advisory: RHOAI 3.4.6 - Red Hat OpenShift AI
- RHSA-2026:87410Red Hat Product SecurityCritical
Red Hat Security Advisory: RHOAI 2.25.12 - Red Hat OpenShift AI
- RHSA-2026:87124Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.7 Container Release Update
- RHSA-2026:87120Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.6 Container Release Update
- +6 more
Patch Availability(16)
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)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python-anyio | 3.6.2-1 ... 4.8.0-3 (24 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python-anyio | 4.11.0-1 ... 4.8.0-3 (10 versions) |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python-anyio | 4.11.0-1 ... 4.8.0-3 (7 versions) |
| — |
PyPI(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| anyio | 1.0.0 ... 4.9.0 (69 versions) |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(2)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
Data Freshness Timeline
(refreshed 25× in last 7d / 145× 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 183 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 83 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-11-01 19:13 UTCEG score recompute
- 2026-11-01 19:13 UTCVendor advisory
- 2026-11-01 19:13 UTCGHSA enrichmentGHSA-82r6-8w77-94w6 · GitHub severity CRITICAL
- 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
- 2026-11-01 07:41 UTCGHSA enrichmentGHSA-82r6-8w77-94w6 · GitHub severity CRITICAL
- 2026-10-31 21:32 UTCEG score recompute
- 2026-10-31 21:32 UTCVendor advisory
- 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
- 2026-10-30 23:52 UTCEG score recompute
- 2026-10-30 23:52 UTCVendor advisory
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.3% · 21st percentile
- 2026-10-30 02:13 UTCEG score recompute
- 2026-10-30 02:13 UTCVendor advisory
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
- 2026-10-29 04:34 UTCEG score recompute
- 2026-10-29 04:34 UTCVendor advisory
- 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
- 2026-10-28 06:45 UTCEG score recompute
- 2026-10-28 06:45 UTCVendor advisory
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
- 2026-10-27 09:06 UTCEG score recompute
- 2026-10-27 09:06 UTCVendor advisory
- 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
- 2026-10-26 10:24 UTCEG score recompute
- 2026-10-26 10:24 UTCVendor advisory
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- 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
- 2026-10-25 14:13 UTCEG score recompute
- 2026-10-25 12:46 UTCEG score recompute
- 2026-10-25 12:46 UTCVendor advisory
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-24 15:03 UTCVendor advisory
- 2026-10-23 17:24 UTCEG score recompute
- 2026-10-23 17:24 UTCVendor advisory
- 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-22 19:45 UTCEG score recompute
- 2026-10-22 19:45 UTCVendor advisory
- 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-21 22:05 UTCEG score recompute
- 2026-10-21 22:05 UTCVendor advisory
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-21 00:00 UTCEG score recompute
- 2026-10-21 00:00 UTCVendor advisory
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-20 02:15 UTCEG score recompute
- 2026-10-20 02:15 UTCVendor advisory
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-19 01:34 UTCEG score recompute
- 2026-10-19 01:34 UTCVendor advisory
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-18 03:53 UTCVendor advisory
- 2026-10-18 03:23 UTCEG score recompute
- 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-17 06:11 UTCEG score recompute
- 2026-10-17 06:11 UTCVendor advisory
- 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-16 07:17 UTCEG score recompute
- 2026-10-16 07:17 UTCVendor advisory
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 20th percentile
- 2026-10-15 06:13 UTCEG score recompute
- 2026-10-15 06:13 UTCVendor advisory
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-14 01:49 UTCEG score recompute
- 2026-10-14 01:49 UTCVendor advisory
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-12 22:02 UTCEG score recompute
- 2026-10-12 22:02 UTCVendor advisory
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-12 15:49 UTCEG score recompute
- 2026-10-12 02:09 UTCVendor advisory
- 2026-10-11 22:23 UTCVendor advisory
- 2026-10-11 19:33 UTCEG score recompute
- 2026-10-11 18:38 UTCVendor advisory
- 2026-10-11 16:48 UTCEG score recompute
- 2026-10-11 14:54 UTCVendor advisory
- 2026-10-11 14:10 UTCEG score recompute
- 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-11 11:09 UTCVendor advisory
- 2026-10-11 07:22 UTCVendor advisory
- 2026-10-11 03:39 UTCVendor advisory
- 2026-10-10 23:45 UTCEG score recompute
- 2026-10-10 23:45 UTCVendor advisory
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-10 20:00 UTCVendor advisory
- 2026-10-10 16:16 UTCVendor advisory
- 2026-10-10 12:30 UTCVendor advisory
- 2026-10-10 08:46 UTCVendor advisory
- 2026-10-10 05:03 UTCVendor advisory
- 2026-10-10 01:19 UTCVendor advisory
- 2026-10-09 21:36 UTCEG score recompute
- 2026-10-09 21:36 UTCVendor advisory
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 19th percentile
- 2026-10-09 17:52 UTCVendor advisory
- 2026-10-09 13:01 UTCVendor advisory
- 2026-10-09 08:20 UTCVendor advisory
- 2026-10-09 04:36 UTCVendor advisory
- 2026-10-09 00:52 UTCVendor advisory
- 2026-10-08 21:09 UTCVendor advisory
- 2026-10-08 17:25 UTCEG score recompute
- 2026-10-08 17:25 UTCVendor advisory
- 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 19th percentile
Related CVEs(same product + same vendor + same CWE)
Same vendor
10 shownredhat:RHSA-2026:84734 · redhat:RHSA-2026:87120 · redhat:RHSA-2026:73929
Frequently asked(5)
What is CVE-2026-63374?
When was the CVE record for CVE-2026-63374 published?
Is CVE-2026-63374 actively exploited?
What is the CVSS score of CVE-2026-63374?
How do I remediate CVE-2026-63374?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-63374
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