CVE-2026-52731
ZEBRA: Full node denial of service via non-ASCII LongPollId in getblocktemplate
Description
ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, an attacker authenticated to an enabled Zebra RPC endpoint can terminate zebrad by supplying a getblocktemplate LongPollId containing multi-byte UTF-8 characters. In zebra-rpc/src/methods/types/long_poll.rs, LongPollId::from_str originally checked the input byte length and then sliced fixed byte ranges to parse encoded fields. A slice boundary can land inside a multi-byte character and trigger Rust's byte index is not a char boundary panic. Zebra release builds use panic equals abort, so one malformed authenticated RPC request terminates the entire node process and can be repeated after restart. This issue is fixed in version 4.5.0.
INFO
Published Date :
Aug. 18, 2026, 8:17 p.m.
Last Modified :
Aug. 18, 2026, 8:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update Zebra to version 4.5.0 or later.
- Disable RPC endpoints if update is not possible.
- Restrict access to RPC endpoints.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-52731.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-52731 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-52731
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-52731 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-52731 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 18, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'ZcashFoundation', 'product': 'zebra', 'versions': [{'status': 'affected', 'version': '< 4.5.0'}]}, {'vendor': 'ZcashFoundation', 'product': 'zebra-rpc', 'versions': [{'status': 'affected', 'version': '< 8.0.0'}]}] Added Description ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, an attacker authenticated to an enabled Zebra RPC endpoint can terminate zebrad by supplying a getblocktemplate LongPollId containing multi-byte UTF-8 characters. In zebra-rpc/src/methods/types/long_poll.rs, LongPollId::from_str originally checked the input byte length and then sliced fixed byte ranges to parse encoded fields. A slice boundary can land inside a multi-byte character and trigger Rust's byte index is not a char boundary panic. Zebra release builds use panic equals abort, so one malformed authenticated RPC request terminates the entire node process and can be repeated after restart. This issue is fixed in version 4.5.0. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-248 Added Reference https://github.com/ZcashFoundation/zebra/commit/1440b43ca7df59aca948090d45117557b217a6cd Added Reference https://github.com/ZcashFoundation/zebra/releases/tag/v4.5.0 Added Reference https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-qv2r-v3mx-f4pf -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 18, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-52731', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-18T19:38:59.310629Z'}