CVE-2026-103415 json
When a TLS 1.3 client processes a HelloRetryRequest, it copies the server's cookie into its second ClientHello without checking that the co…
published 26d ago modified 24d ago also EUVD-2026-101501
- cvss
- 9.3
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 21%
- public exploits
- 0
- none known
Summary
When a TLS 1.3 client processes a HelloRetryRequest, it copies the server's cookie into its second ClientHello without checking that the cookie fits in the outgoing packet. Both the length and the contents of that cookie come from the peer, and the write happens before certificate authentication completes, so a malicious or compromised server can overwrite memory past the caller supplied TLS packet buffer without presenting a certificate.
Only the client path is affected.
Patch / fix
- Eclipse Foundation NetX Duo 6.5.2.202603
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 24d ago
Exploit prediction
0.28% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CNA | 4.0 | 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- Eclipse Foundation NetX Duo
Classification
- Weakness
-
- CWE-787 Out-of-bounds Write
References
Sources
- CVE List CVE-2026-103415
- NVD CVE-2026-103415
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.