NVD / CVE Program· CNA GitHub_M

CVE-2026-34227: Sliver One-Click Remote Access: Insecure CORS & Unauthenticated MCP Interface

Noroxi assessment

Priority: Monitor (action score 23/100)

Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 0.41% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No special conditions are required; it is repeatable.
Fixed version: BishopFox sliver 1.7.4.

Low priority for now. Upgrade to BishopFox sliver 1.7.4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Sliver is a command and control framework that uses a custom Wireguard netstack. Prior to version 1.7.4, a single click on a malicious link gives an unauthenticated attacker immediate, silent control over every active C2 session or beacon, capable of exfiltrating all collected target data (e.g. SSH keys, ntds.dit) or destroying the entire compromised infrastructure, entirely through the operator's own browser. This issue has been patched in version 1.7.4.

MediumCVSS 5.9 · v4.0—Proof of concept Fix available

Published: Mar 31, 2026
Updated: Jul 24, 2026
EPSS: 0.4% · 35th percentile
CWE: CWE-306

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 23 / 40 · 5.9 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.4%

CISA SSVC decision

Exploitation: proof of concept
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · GitHub_M: 5.9; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
Proof of concept exists, no weaponized module
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
bishopfox	sliver	cpe:2.3:a:bishopfox:sliver

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

bishopfox sliverbefore 1.7.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

BishopFox sliver
- < 1.7.4affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Go	github.com/bishopfox/sliver	before 1.7.4	1.7.4

Same product

bishopfox: all records

Other highest-scoring records for the same primary product.

CVE-2026-77622Sliver: Unauthenticated Memory Exhaustion Denial of Service in Sliver HTTP(S) Listener PNG Decoder
32Monitor
CVE-2023-34758Sliver from v1.5.x to v1.5.39 has an improper cryptographic implementation, which allows attackers to execute a man-in-the-middle attack via
32Monitor
CVE-2026-25791Sliver has a DNS C2 OTP Bypass Allows Unauthenticated Session Flooding and Denial of Service
30Monitor

Published before and after this one in the same product

← EarlierCVE-2026-29781Mar 7, 2026 · Sliver: Authenticated Nil-Pointer Dereference in Handlers
8Monitor
← EarlierCVE-2026-32941Mar 20, 2026 · Sliver Vulnerable to Authenticated OOM via Memory Exhaustion in mTLS/WireGuard Transports
22Monitor
Later →CVE-2026-102507Sep 29, 2026 · Sliver 1.7.7 Denial of Service via PE Parser Slice Bounds in Operator RPC
27Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
BishopFox sliver	1.7.4 · description	Vendor (CNA)
Go:github.com/bishopfox/sliver	1.7.4	Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Proof-of-concept repository on GitHub	stars:1	2026-03-27

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

First PoCMar 27, 2026-5 d
PublishedMar 31, 2026
TodayNov 8, 2026+222 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-2579150 days apartSliver has a DNS C2 OTP Bypass Allows Unauthenticated Session Flooding and Denial of Service
30Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

CVE-2026-2576053 days apartWebsite Path Traversal / Arbitrary File Read (Authenticated) in Sliver
26Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: A
Scope: X

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Root cause

A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”

The bug in code

The whole CWE-306 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1// Added for the support team
2app.post("/maintenance/reset", resetDevice);

Fixed

1if (config.maintenanceEnabled) {
2  app.post(
3    "/maintenance/reset",
4    requireSession, requireRole("admin"), resetDevice
5  );
6}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log

Fix✗ → ✓Sep 28, 2026, 10:45 PM UTC

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