CVE-2026-104424 (CVSS 3.7)

Description

Zebra before 6.1.0 contains an incorrect calculation vulnerability in its ZIP-317 block template selector that omits header and transaction-count size from the block budget. Attackers can place valid selectable transactions in a victim miner's mempool to shape templates into oversized blocks, causing rejection and wasted proof-of-work.

Is your site exposed to CVE-2026-104424?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

3.7

LOW

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS — Exploit Prediction

0.0027

Probability of exploitation

0.19%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-131 CWE-131

References

Other References

https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-95m2-vx53-v2jw https://www.vulncheck.com/advisories/zebra-before-6.1.0-incorrect-block-size-calculation-in-getblocktemplate

Frequently Asked Questions

What is CVE-2026-104424? +

Zebra before 6.1.0 contains an incorrect calculation vulnerability in its ZIP-317 block template selector that omits header and transaction-count size from the block budget. Attackers can place valid selectable transactions in a victim miner's mempool to shape templates into oversized blocks, causing rejection and wasted proof-of-work. It has a CVSS v3.1 base score of 3.7 (LOW).

How severe is CVE-2026-104424? +

CVE-2026-104424 has a CVSS v3.1 score of 3.7 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0027, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-104424? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-11604

An incorrect buffer size calculation in the epoch key generator in OpenVPN ovpn-dco-win version 2.0.0 through 2.8.3 allows a remote …

CVE-2026-95111

A memory-protected ThreadX module's queue request reaches the Module Manager's dispatch layer, which decides how much of the module's buffer …

CVE-2026-45784

rust-openssl provides OpenSSL bindings for the Rust programming language. From 0.10.50 until 0.10.80, CipherCtxRef::cipher_update_inplace in openssl/src/cipher_ctx.rs incorrectly sized output buffers …

CVE-2026-102729

`gx_binres_theme_load()` sizes its theme buffer for the theme it was asked for, and allocates it even when the resource holds …

CVE-2026-47773

ArduinoBLE enables Bluetooth Low Energy connectivity on certain Arduino models. Versions prior to 2.0.2 contain a missing bounds check in …

CVE-2026-78221

An incorrect buffer size calculation in the Windows Interactive Service in OpenVPN 2.7_alpha1 through 2.7.6 allows local authenticated users to …

CVE-2026-104424