DEBIAN-CVE-2026-3706
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."
DEBIAN-CVE-2026-3706
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-3706
dropbear
Source reference: /affected/0/package/name
- Affected versions
- 2022.83-1
Source reference:
/affected/0/versions2022.83-1+deb12u1Source reference:
/affected/0/versions2022.83-1+deb12u1~bpo11+1Source reference:
/affected/0/versions2022.83-1+deb12u2Source reference:
/affected/0/versions2022.83-1+deb12u3Source reference:
/affected/0/versions2022.83-2Source reference:
/affected/0/versions2022.83-3Source reference:
/affected/0/versions2022.83-4Source reference:
/affected/0/versions2024.84-1Source reference:
/affected/0/versions2024.85-1Source reference:
/affected/0/versions2024.85-2Source reference:
/affected/0/versions2024.85-3Source reference:
/affected/0/versions2024.86-1Source reference:
/affected/0/versions2024.86-2Source reference:
/affected/0/versions2025.87-1Source reference:
/affected/0/versions2025.88-1Source reference:
/affected/0/versions2025.88-2Source reference:
/affected/0/versions2025.89-1Source reference:
/affected/0/versions2025.89-1~deb13u1Source reference:
/affected/0/versions2026.90-1Source reference:
/affected/0/versions2026.91-1Source reference:
/affected/0/versions2026.92-1Source reference:
/affected/0/versions2026.93-1Source reference:
/affected/0/versions2026.94-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
dropbear
Source reference: /affected/1/package/name
- Affected versions
- 2025.88-2
Source reference:
/affected/1/versions2025.89-1Source reference:
/affected/1/versions2025.89-1~deb13u1Source reference:
/affected/1/versions2026.90-1Source reference:
/affected/1/versions2026.91-1Source reference:
/affected/1/versions2026.92-1Source reference:
/affected/1/versions2026.93-1Source reference:
/affected/1/versions2026.94-1Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
dropbear
Source reference: /affected/2/package/name
- Affected versions
- 2025.88-2
Source reference:
/affected/2/versions2025.89-1Source reference:
/affected/2/versions2025.89-1~deb13u1Source reference:
/affected/2/versions - Fixed versions
- 2026.90-1
Source reference:
/affected/2/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "dropbear",
"purl": "pkg:deb/debian/dropbear?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"2022.83-1",
"2022.83-1+deb12u1",
"2022.83-1+deb12u1~bpo11+1",
"2022.83-1+deb12u2",
"2022.83-1+deb12u3",
"2022.83-2",
"2022.83-3",
"2022.83-4",
"2024.84-1",
"2024.85-1",
"2024.85-2",
"2024.85-3",
"2024.86-1",
"2024.86-2",
"2025.87-1",
"2025.88-1",
"2025.88-2",
"2025.89-1",
"2025.89-1~deb13u1",
"2026.90-1",
"2026.91-1",
"2026.92-1",
"2026.93-1",
"2026.94-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-3706.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "dropbear",
"purl": "pkg:deb/debian/dropbear?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"2025.88-2",
"2025.89-1",
"2025.89-1~deb13u1",
"2026.90-1",
"2026.91-1",
"2026.92-1",
"2026.93-1",
"2026.94-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-3706.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2026.90-1"
}
]
}
],
"package": {
"name": "dropbear",
"purl": "pkg:deb/debian/dropbear?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"2025.88-2",
"2025.89-1",
"2025.89-1~deb13u1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-3706.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #55995 · Revision 1
- Added to Heist Feed
- Publisher date