PT-2026-55467 · Crates.Io · Zebra-Rpc+1

Publicado 2026-07-02 · Atualizado 2026-07-02 · CVE-2026-52731

OSV

CVSS v3.1

6.5

Média

Vetor base

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected

You are affected if:

1. You run zebrad up to and including v4.4.1.
2. Your zebrad.toml sets rpc.listen addr to a TCP address (RPC server is enabled).
3. An attacker can authenticate to the RPC endpoint. With the default enable cookie auth = true, this requires the attacker to read the .cookie file. With enable cookie auth = false, any network client reaching the RPC port can trigger it.

Summary

The getblocktemplate RPC handler panics when parsing a LongPollId parameter that contains non-ASCII (multi-byte UTF-8) characters. The handler performs byte-index string slicing on the user-supplied string, which panics in Rust when a byte index falls within a multi-byte character boundary. Because Zebra's release profile sets panic = "abort", the panic terminates the entire node process.

Details

The getblocktemplate handler receives a user-supplied LongPollId string and slices it at fixed byte offsets to extract the encoded tip hash and tip height. When the string contains multi-byte UTF-8 characters, a byte-index slice can land in the middle of a character, causing Rust's str indexing to panic with "byte index is not a char boundary."

Under the panic = "abort" release profile, this panic terminates the entire zebrad process rather than just the RPC task.

Patches

zebra-rpc 8.0.0 and zebrad 4.5.0.

Replace byte-index string slicing with character-aware parsing or validate that the LongPollId string contains only ASCII characters before slicing.

Workarounds

• Disable the RPC server by removing rpc.listen addr from zebrad.toml.
• Ensure enable cookie auth = true (the default) and restrict filesystem access to the .cookie file.
• Place a reverse proxy in front of the RPC port that validates LongPollId parameters are ASCII-only before forwarding.

Impact

A single authenticated RPC request terminates the zebrad process. Same impact profile as GHSA-c8w6-x74f-vmg3: repeatable on restart, affects mining pools and infrastructure that forward getblocktemplate calls.

Credit

Reported by @sangsoo-osec via a private GitHub Security Advisory submission.

Correção

Enumeração de Fraquezas

CWE-248

Identificadores relacionados

CVE-2026-52731

GHSA-QV2R-V3MX-F4PF

Produtos afetados

Zebra-Rpc

Zebrad

Referências · 4

• https://github.com/ZcashFoundation/zebra · Nota
• https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-qv2r-v3mx-f4pf · Nota
• https://github.com/ZcashFoundation/zebra/blob/d4cd662c716382f6397d2a730148025a1ca79fec/Cargo.toml#L305 · Nota
• https://osv.dev/vulnerability/GHSA-qv2r-v3mx-f4pf · Aviso do Fabricante