CVE-2026-25793

Nebula Has Possible Blocklist Bypass via ECDSA Signature Malleability

HIGH
8.1
CVSS Score
Published: February 6, 2026 at 10:55 PM UTC
Updated: June 17, 2026 at 10:25 AM UTC
2 products affected across 2 vendorsNebulaNebula

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Severity
HIGH8.1
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

Description

Nebula is a scalable overlay networking tool. In versions from 1.7.0 to 1.10.2, when using P256 certificates (which is not the default configuration), it is possible to evade a blocklist entry created against the fingerprint of a certificate by using ECDSA Signature Malleability to use a copy of the certificate with a different fingerprint. This issue has been patched in version 1.10.3.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

1.7.0 ≤ v < 1.10.3
v < 1.10.3
Affected range stops below 1.10.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-347

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