idn2_to_ascii_4i in lib/lookup.c in GNU libidn2 before 2.1.1 has a heap-based buffer overflow via a long domain string.
Priority MEDIUM 48CWE-787Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.
Summary
idn2_to_ascii_4i in lib/lookup.c in GNU libidn2 before 2.1.1 has a heap-based buffer overflow via a long domain string.
Why it matters now
EPSS 0.03708 89th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat CodeReady Linux Builder (v. 8) | Fixed | — |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | — |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | — |
Timeline
- 2026-10-02 Threatist record created from CVE-2019-18224
- 2026-10-03 Alias added: GHSA-j2c9-63g7-697x
References
Advisory 8
More GNU Libidn2 vulnerabilities
- TI-2017-10238 Integer overflow in the decode_digit function in puny_decode.c in Libidn2 before 2.0.4… CVSS 3.1CRITICAL 9.8
- TI-2017-10237 Integer overflow in the _isBidi function in bidi.c in Libidn2 before 2.0.4 allows remote… CVSS 3.0CRITICAL 9.8
- TI-2019-09168 GNU libidn2 before 2.2.0 fails to perform the roundtrip checks specified in RFC3490… CVSS 3.1HIGH 7.5
Sources
- CVE-2019-18224 · CVE Program
- CVE-2019-18224 · NVD
- FIRST EPSS
- GHSA-j2c9-63g7-697x · GitHub Advisory Database · CC BY 4.0
- CVE-2019-18224 · Red Hat security data · CC BY 4.0
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