CVE-2026-33471: nimiq-block · Improper Input Validation
Affects nimiq-blockSource CVE Database V5
Not known to be exploited · CVSS 9.6 Critical : upgrade to 1.3.0 as a priority.
Data as of 30 Oct 2026, 11:52 UTC
Contested
Critical score, yet low EPSS after six months- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.3.0
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 22 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade nimiq-block and github/nimiq/nimiq-block to 1.3.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| nimiqnimiq-block | Affected
| Fixed in
|
crates.iogithub/nimiq/nimiq-blockpkg:cargo/github/nimiq/nimiq-blockOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade to nimiq-block version 1.3.0 or later, which includes the official fix for this vulnerability. No other workarounds or mitigations are available. Users should apply this patch promptly to prevent exploitation.
Description
CVE-2026-33471 is a critical vulnerability in the nimiq-block Rust implementation prior to version 1.3.0. It involves improper input validation in the SkipBlockProof::verify function, where out-of-range signer indices can be exploited to bypass quorum checks. This allows a malicious validator with fewer than the required number of signer slots to pass verification by manipulating signature aggregation. The vulnerability has a CVSS score of 9.6, indicating high impact on integrity and availability. A patch fixing this issue was included in version 1.3.0.