Security readout for executives and security teams
Plain-English summary
Hono’s IP restriction middleware could fail to block an IP address if the same IPv6 address was written in a different valid format. A denied address could therefore be allowed through. The issue affects Hono versions before 4.12.21 and is fixed in 4.12.21.
Executive priority
Treat this as a targeted access-control bypass, not a broad system compromise. Upgrade soon if Hono IP restrictions protect sensitive routes or operational interfaces. Business urgency is higher where IP rules are the primary boundary.
Technical view
Before 4.12.21, hono/ip-restriction compared incoming IPs to static allow/deny rules using string equality after incomplete normalization. Equivalent non-canonical IPv6 forms, including compressed, explicit-zero, or hex-notation IPv4-mapped addresses, could miss configured rules and bypass intended access control.
Likely exposure
Exposure is limited to applications using Hono before 4.12.21 with the ip-restriction middleware and static IP allow or deny rules. Systems relying on those rules for access control over IPv6 or IPv4-mapped IPv6 traffic are the main concern.
Exploitation context
The CVSS vector indicates remote, unauthenticated, low-complexity exploitation with no user interaction, but limited impact. The provided sources do not report active exploitation, and the CVE is not marked as KEV in the source bundle.
Researcher notes
The root issue is incomplete IP canonicalization combined with string equality for static rules. Evidence names Hono before 4.12.21 and the ip-restriction middleware only. Do not generalize this to other Hono middleware without separate evidence.
Mitigation direction
- Upgrade Hono to version 4.12.21 or later.
- Prioritize apps where IP restriction protects admin, API, or partner-only routes.
- Review vendor advisory for any additional operational guidance.
- Avoid relying solely on IP rules for sensitive authorization decisions.
Validation and detection
- Inventory deployed Hono versions and package lockfiles.
- Confirm whether hono/ip-restriction is used in production code.
- Review static allow and deny rules for IPv6-dependent access control.
- Add regression tests for equivalent IPv6 representations against configured rules.
- Check access logs for unexpected access to IP-restricted routes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-1289: Exact CWE lookup
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Open ATT&CK lookupCWE-185: Exact CWE lookup
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Open ATT&CK lookupCVE-2026-47674 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N3.91.4GitHub_MVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/honojs/hono/security/advisories/GHSA-xrhx-7g5j-rcj5CVE reference, GitHub_M · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Validation of Unsafe Equivalence in Input
Improper Validation of Unsafe Equivalence in Input represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Incorrect Regular Expression
Incorrect Regular Expression represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.