How severe is GHSA-69x3-g4r3-p962?

No CVSS score has been assigned to GHSA-69x3-g4r3-p962 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-69x3-g4r3-p962?

GHSA-69x3-g4r3-p962 affects the following packages: github.com/slackhq/nebula (Go). Ecosystems affected: Go.

How do I fix GHSA-69x3-g4r3-p962?

Update github.com/slackhq/nebula to 1.10.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-69x3-g4r3-p962 is resolved across your whole dependency graph.

How do I detect GHSA-69x3-g4r3-p962 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/slackhq/nebula, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-69x3-g4r3-p962 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is GHSA-69x3-g4r3-p962 actively exploited in the wild?

No public exploit code has been indexed for GHSA-69x3-g4r3-p962 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-69x3-g4r3-p962?

GHSA-69x3-g4r3-p962 has an EPSS (Exploit Prediction Scoring System) score of 0.1%, placing it in the 4th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-69x3-g4r3-p962?

GHSA-69x3-g4r3-p962 is classified as CWE-347 (CWE-347). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-69x3-g4r3-p962 published, and has it been updated?

GHSA-69x3-g4r3-p962 was published on February 6, 2026 and was last updated on September 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

Blocklist Bypass possible via ECDSA Signature MalleabilityGHSA-69x3-g4r3-p962

Fix: slackhq/nebula@f573e8a

GHSA-69x3-g4r3-p962 is a CWE-347 vulnerability in github.com/slackhq/nebula. A fix is available for github.com/slackhq/nebula — see the affected versions and patch details below.

Also known asCVE-2026-25793GO-2026-4458

Published

Feb 6, 2026

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 9, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-69x3-g4r3-p962.

EPSS Exploitation Probability

via FIRST.org ↗

0.1%probability of exploitation in next 30 days

Lower Risk-0.00%

Lower risk than most CVEs4th percentile — riskier than 4% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐹github.com/slackhq/nebula

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Impact

When using P256 certificates (which is not the default configuration), it is possible to evade a blocklist entry created against the fingerprint of a certificate by using ECDSA Signature Malleability to use a copy of the certificate with a different fingerprint.

In order for this to affect a user or network, all of the following must be true:

CURVE_P256 certificates are being used
There are one or more entries on the blocklist
The certificates for those entries are signed by a trusted CA and not expired
An attacker has a copy of the private key, and corresponding certificate, for one of those blocklist entries

Patches

See attached

Workarounds

If full copies of each certificate on the existing blocklist are available, it is possible to compute their opposite-chirality signature, and then the appropriate second fingerprint to list in the blocklist.

Rotating out all CAs that have signed hosts on the blocklist will also prevent exploitation of this vulnerability.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/slackhq/nebula`	≥ 1.7.0&&< 1.10.3	1.10.3`go get github.com/slackhq/nebula@v1.10.3`

Affected Products

1 product · 1 configurations

Application

nebulaslack

≥ 1.7.0 && < 1.10.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/slackhq/nebula, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/slackhq/nebula to 1.10.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-69x3-g4r3-p962 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

While the flaw is rated as Important, please keep in mind that there are several preconditions that must be true for a customer to be impacted: 1. They must be used CURVE_P256 certificates (which are not the default). 2. They must have one or more entries on their blocklist. 3. The certificates of those blocklisted…

Workaround published by Red Hat

Avoid configuring Nebula to use P256 certificates. This vulnerability is only exploitable when P256 certificates are explicitly enabled, as they are not the default configuration. Ensure Nebula deployments utilize default or other non-P256 certificate types to prevent blocklist evasion.

Source: Red Hat security advisory for GHSA-69x3-g4r3-p962 (CC BY 4.0)

Frequently Asked Questions

### Impact When using P256 certificates (which is not the default configuration), it is possible to evade a blocklist entry created against the fingerprint of a certificate by using ECDSA Signature Malleability to use a copy of the certificate with a different fingerprint. In order for this to affect a user or network, all of the following must be true: * `CURVE_P256` certificates are being used * There are one or more entries on the blocklist * The certificates for those entries are signed by a trusted CA and not expired * An attacker has a copy of the private key, and corresponding certifi