CVE-2026-49834

sigstore-go: Multi-log threshold bypass via single compromised log

HIGH
7.5
CVSS Score
Published: July 17, 2026 at 07:20 PM UTC
Updated: October 24, 2026 at 08:10 PM UTC
1 product affected across 1 vendorSigstore Go

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Severity
HIGH7.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

sigstore-go is a Go library for Sigstore signing and verification. Prior to 1.2.0, a verifier configured with WithTransparencyLog(N>1) or WithSignedCertificateTimestamps(N>1) counts verified witnesses per entry or per validation path rather than per log authority, allowing a single compromised transparency log or CT log to satisfy multi-log threshold requirements and defeat the multi-log policy. This issue is fixed in version 1.2.0.

Affected

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

v < 1.2.0
Affected range stops below 1.2.0, so it looks safe — our inference, not a vendor statement

References (4)

x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/sigstore/sigstore-go/pull/633
x_refsource_MISCProductRelease Notes
Source: cverecord
https://github.com/sigstore/sigstore-go/releases/tag/v1.2.0

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
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-347

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