Zebra from 2.3.0 before 7.0.0 contains a denial of service vulnerability that allows unauthenticated peers to evade
Source GCVE Database
Not known to be exploited · CVSS 8.7 High : upgrade to 7.0.0 soon.
Data as of 8 Nov 2026, 06:36 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 8.7 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 7.5 |
- Patch
- Available – fixed in 7.0.0, 18.0.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 8 Nov 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 7 Nov 2026.
What to do
Upgrade zebra to 7.0.0; zebra to 18.0.0; zebra to 18.0.0 or 7.0.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| ZcashFoundationzebra | Affected
| Fixed in
|
| ZcashFoundationzebra | Affected
| Fixed in
|
crates.iozebrapkg:cargo/zebraOther 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
If you cannot patch yet, monitoring for unusual mempool activity and limiting peer connections from untrusted sources may help mitigate risk, but these are not confirmed vendor recommendations.
Description
Zebra versions from 2.3.0 up to but not including 7.0.0 have a denial of service vulnerability. This flaw allows unauthenticated peers to bypass misbehavior scoring by submitting transactions or blocks containing invalid transparent scripts. Exploitation can lead to mempool flooding with script-failing transactions or delivery of forged v5 block bodies with altered scriptSig bytes, causing CPU exhaustion and repeated stalling of block synchronization.
References
- github.com/ZcashFoundation/zebra/security/advisories/GHSA-jq45-ghw5-v37x (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-123555 (opens in a new tab)
- github.com/ZcashFoundation/zebra/commit/e8db87eb69254e0d4eedd058eadd48bdfa09065a (opens in a new tab)
- vulncheck.com/advisories/zebra-2.3.0-before-7.0.0-denial-of-service-via-unscored-script-verification-failures (opens in a new tab)