Summary
nimiq-primitives: Out-of-bounds panic in KeyNibbles::Add from oversized child suffix in a deserialized proof
Workarounds
None other than syncing only from trusted peers. Upgrade to 1.6.0.
Impact
A malicious peer acting as a state-sync source can crash a syncing node with a crafted TrieChunk whose proof contains a TrieNodeChild whose suffix, when concatenated with the parent key via KeyNibbles::Add, exceeds the fixed 63-byte backing array. Add (primitives/src/key_nibbles.rs:332 / :341) indexes bytes[self.bytes_len()..self.bytes_len() + other.bytes_len()] with no combined-length check, causing an out-of-bounds slice panic (both the even- and odd-length branches).
KeyNibbles deserialization validates only the individual length <= 126, not the combined parent + suffix length. The panic occurs at put_chunk → child.key() → is_stump() → +, i.e. before proof.verify(), so no valid proof is required. As with the related child_index issue, exploitation requires being the victim's sync peer during state sync, and the resulting crash is transient (the node restarts and re-syncs).
Affected: core-rs-albatross <= 1.5.1 (nimiq-primitives).
A read operation accesses a memory location beyond the intended buffer boundary. Typical impact: sensitive data disclosure or crash.
CVE-2026-54542 has a CVSS score of 3.7 (Low). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.6.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Fixed in 1.6.0 via https://github.com/nimiq/core-rs-albatross/pull/3790 (commit eabfc3e2), which guards key-nibble concatenation against exceeding the maximum length instead of indexing out of bounds.
Frequently Asked Questions
- What is CVE-2026-54542? CVE-2026-54542 is a low-severity out-of-bounds read vulnerability in nimiq-primitives (rust), affecting versions < 1.6.0. It is fixed in 1.6.0. A read operation accesses a memory location beyond the intended buffer boundary.
- How severe is CVE-2026-54542? CVE-2026-54542 has a CVSS score of 3.7 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of nimiq-primitives are affected by CVE-2026-54542? nimiq-primitives (rust) versions < 1.6.0 is affected.
- Is there a fix for CVE-2026-54542? Yes. CVE-2026-54542 is fixed in 1.6.0. Upgrade to this version or later.
- Is CVE-2026-54542 exploitable, and should I be worried? Whether CVE-2026-54542 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-54542 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-54542? Upgrade
nimiq-primitivesto 1.6.0 or later.