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CVE-2021-4070Off-by-one Error in v2fly/v2ray-core
- 5.9MediumCVSS base score
- 0.86%Exploitation in 30 daysEPSS · top 41% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Off-by-one Error in GitHub repository v2fly/v2ray-core prior to 4.44.0.
Timeline
ID reserved
By @huntrdev
- 3 months later
· 3 months later
Published
- 2 years later
· 2 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| @huntrdevCNA (assigner) | 3.0 | Medium5.9 | CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| NVDNVD · Modified | 3.1 | Critical9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.86% · top 41% of all CVEs (14 Nov 2026)
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.9.
Affected products
- affected unspecified – < 4.44.0
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/v2fly/v2ray-coreGHSA-4cxw-hq44-r344 (opens in a new tab)
- Gogithub.com/v2fly/v2ray-core/v4GHSA-4cxw-hq44-r344 (opens in a new tab)
References
References2
- https://huntr.dev/bounties/8da19456-4d89-41ef-9781-a41efd6a1877 (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://github.com/v2fly/v2ray-core/commit/c1af2bfd7aa59a4482aa7f6ec4b9208c1d350b5c (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2022-0809 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-4cxw-hq44-r344 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2021-4070)Record last updated .