nimiq core-rs-albatross up to 1.2.x SkipBlockProof::verify input validation

CVSS Meta Temp Score
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CTI Interest Score
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7.4$0-$5k4.56

Summaryinfo

A vulnerability, which was classified as problematic, has been found in nimiq core-rs-albatross up to 1.2.x. This affects the function SkipBlockProof::verify. This manipulation causes input validation. The identification of this vulnerability is CVE-2026-33471. It is possible to initiate the attack remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in nimiq core-rs-albatross up to 1.2.x and classified as problematic. Affected by this vulnerability is the function SkipBlockProof::verify. The manipulation with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect integrity, and availability. The summary by CVE is:

nimiq/core-rs-albatross is a Rust implementation of the Nimiq Proof-of-Stake protocol based on the Albatross consensus algorithm. `SkipBlockProof::verify` computes its quorum check using `BitSet.len()`, then iterates `BitSet` indices and casts each `usize` index to `u16` (`slot as u16`) for slot lookup. Prior to version 1.3.0, if an attacker can get a `SkipBlockProof` verified where `MultiSignature.signers` contains out-of-range indices spaced by 65536, these indices inflate `len()` but collide onto the same in-range `u16` slot during aggregation. This makes it possible for a malicious validator with far fewer than `2f+1` real signer slots to pass skip block proof verification by multiplying a single BLS signature by the same factor. The patch for this vulnerability is included as part of v1.3.0. No known workarounds are available.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-33471 since 03/20/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 1.3.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch d02059053181ed8ddad6b59a0adfd661ef5cd823 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

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Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.4

VulDB Base Score: 5.4
VulDB Temp Score: 5.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 9.6
CNA Vector (GitHub_M): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: core-rs-albatross 1.3.0
Patch: d02059053181ed8ddad6b59a0adfd661ef5cd823

Timelineinfo

03/20/2026 CVE reserved
04/22/2026 +32 days Advisory disclosed
04/22/2026 +0 days VulDB entry created
04/22/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-6973-8887-87ff
Status: Confirmed

CVE: CVE-2026-33471 (🔒)
GCVE (CVE): GCVE-0-2026-33471
GCVE (VulDB): GCVE-100-359059

Entryinfo

Created: 04/22/2026 22:31
Changes: 04/22/2026 22:31 (67)
Complete: 🔍
Cache ID: 216::103

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