How severe is CVE-2026-48058?

No CVSS score has been assigned to CVE-2026-48058 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-48058?

CVE-2026-48058 affects the following packages: github.com/juev/nebula-mesh (Go). Ecosystems affected: Go.

How do I fix CVE-2026-48058?

Update github.com/juev/nebula-mesh to 0.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48058 is resolved across your whole dependency graph.

How do I detect CVE-2026-48058 in my Go dependencies?

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

How do I mitigate CVE-2026-48058 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 CVE-2026-48058 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-48058 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 CVE-2026-48058?

CVE-2026-48058 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 23th 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 CVE-2026-48058?

CVE-2026-48058 is classified as CWE-614 (CWE-614). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-48058 published, and has it been updated?

CVE-2026-48058 was published on July 28, 2026 and was last updated on October 21, 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

CVE-2026-48058 — nebula-mesh

Fix: forgekeep/nebula-mesh@ffdd67d

CVE-2026-48058 is a CWE-614 vulnerability in github.com/juev/nebula-mesh. A fix is available for github.com/juev/nebula-mesh — see the affected versions and patch details below.

nebula-mesh: Session and OIDC state cookies lack the Secure attribute

Also known asGHSA-rqfj-vv8r-xhqcGO-2026-5635

Published

Jul 28, 2026

Updated

Oct 21, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 20, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs23th percentile — riskier than 23% 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/juev/nebula-mesh

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

internal/web/session.go and internal/web/oidc.go set HttpOnly and SameSite=Lax on every cookie but never Secure. A single plaintext request to the origin (operator on a LAN, mistyped URL, HTTP→HTTPS not strictly enforced, reverse proxy misconfiguration) discloses the session.

Affected

All released versions up to v0.3.1.

Impact

An attacker who can observe one HTTP request to the origin recovers the session cookie and impersonates the operator for the remainder of its 24h TTL. The OIDC state cookie has a narrower 10-minute window but enables CSRF on the OIDC callback during that window.

Cookie sites

internal/web/session.go — Login, StartAuthenticatedSession, CompleteTwoFactor, Logout
internal/web/oidc.go — HandleLogin (state set), HandleCallback (state clear)

Suggested fix

Driven by an explicit cookie_secure config option, inferred true when tls_cert+tls_key are configured and false otherwise. rate_limit.trust_proxy_header is deliberately not used as a signal — that flag controls XFF parsing for rate-limit IPs and does not promise the proxy speaks TLS to clients. Operator behind a TLS-terminating proxy sets cookie_secure: true explicitly.

Logout and OIDC state-clear cookies also pick up matching HttpOnly + SameSite=Lax so browsers reliably replace the original.

Reproducer

Start nebula-mgmt without tls_cert/tls_key (the documented "behind a reverse proxy" deployment). Hit any login flow over the local listener:

curl -i -X POST -d 'username=admin&password=…' http://127.0.0.1:8080/ui/login

The Set-Cookie: nebula_session=… line will lack Secure. A subsequent unencrypted hop reveals the cookie verbatim.

Operational migration

Operators flipping cookie_secure on a running deployment should expect a one-time logout: existing browser cookies have the old attribute set and the new delete-cookie won't match.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/juev/nebula-mesh`	all versions	0.3.2`go get github.com/juev/nebula-mesh@v0.3.2`

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/juev/nebula-mesh, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/juev/nebula-mesh to 0.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48058 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.

Frequently Asked Questions

`internal/web/session.go` and `internal/web/oidc.go` set `HttpOnly` and `SameSite=Lax` on every cookie but never `Secure`. A single plaintext request to the origin (operator on a LAN, mistyped URL, HTTP→HTTPS not strictly enforced, reverse proxy misconfiguration) discloses the session. ## Affected All released versions up to v0.3.1. ## Impact An attacker who can observe one HTTP request to the origin recovers the session cookie and impersonates the operator for the remainder of its 24h TTL. The OIDC state cookie has a narrower 10-minute window but enables CSRF on the OIDC callback during tha

O3 Security · Impact-Aware SCA

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CVE-2026-48058 — nebula-mesh

EPSS Exploitation Probability

Real-World Exposure

Description

Affected

Impact

Cookie sites

Suggested fix

Reproducer

Operational migration

Affected Packages

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2026-48058 in your dependencies?