CVE-2026-3706

LOW EPSS 5.7%
Published Mar 8, 20263mo ago · Modified Jun 17, 20261w ago
1.7 CVSS 4.0
Low
Find Similar
Published Mar 8, 2026 3mo ago
Last Modified Jun 17, 2026 1w ago

Description

A vulnerability was determined in mkj Dropbear up to 2025.89. Impacted is the function unpackneg of the file src/curve25519.c of the component S Range Check. This manipulation causes improper verification of cryptographic signature. The attack can be initiated remotely. The attack is considered to have high complexity. The exploitability is considered difficult. The actual existence of this vulnerability is currently in question. Patch name: fdec3c90a15447bd538641d85e5a3e3ac981011d. To fix this issue, it is recommended to deploy a patch. The project maintainer explains: "Signature Malleability is not exploitable in SSH protocol. (...) [A] PoC doesn't exist for SSH implementation, but rather it's against the internal API."

CVSS Details

Base Score
1.7
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/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
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
5.7% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 2

CWE-345
CWE-347

References 8

  • github.com https://github.com/mkj/dropbear/
  • github.com https://github.com/mkj/dropbear/commit/fdec3c90a15447bd538641d85e5a3e3ac981011d
  • github.com https://github.com/mkj/dropbear/issues/406
  • github.com https://github.com/mkj/dropbear/pull/407
  • github.com https://github.com/str4d/ed25519-java/issues/82#issue-727629226
  • vuldb.com https://vuldb.com/?ctiid.349652
  • vuldb.com https://vuldb.com/?id.349652
  • vuldb.com https://vuldb.com/?submit.765933

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.