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NVD / CVE Program· CNA VulnCheck

CVE-2026-48558: SimpleHelp Authentication Bypass via Missing OIDC JWT Signature Verification

Noroxi assessment

Priority: Now (action score 91/100)

  • CISA has confirmed exploitation in the wild (Jun 29, 2026). Remediation deadline for US federal agencies: Jul 2, 2026.
  • A ready-made attack module is public (Metasploit, Nuclei); exploiting it takes no special expertise.
  • Probability of exploitation in the next 30 days: 77.6% (FIRST EPSS); higher than 99.5% of all records.
  • This probability rose by 72 points in the last 7 days.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: SimpleHelp SimpleHelp 5.5.16.

Patch today or shut off access. Upgrade to SimpleHelp SimpleHelp 5.5.16 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 · CISA KEV · FIRST EPSS

SimpleHelp versions 5.5.15 and prior and 6.0 pre-release versions contain an authentication bypass vulnerability in the OIDC authentication flow. When OIDC authentication is configured, identity tokens submitted during login are accepted without verifying their cryptographic signature. In a vulnerable configuration, a remote, unauthenticated attacker can submit a forged token containing arbitrary identity claims to obtain a fully authenticated technician session. In some configurations, this may also allow bypass of multi-factor authentication. No user interaction is required.

CriticalCVSS 9.5 · v4.0KEVWeaponized Fix available
Published
Jun 12, 2026
Updated
Oct 7, 2026
EPSS
77.6% · 99th percentile▲ 72

Report tools

JSON

Action score

91

Now

Patch today or shut off access.

CVSS
38 / 40 · 9.5 / 10
CISA KEV
30 / 30 · Listed
EPSS
23 / 30 · 77.6%

CISA SSVC decision

Exploitation
active
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulnCheck
9.5
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:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

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

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Jun 29, 2026. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Jul 2, 2026.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-48558

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

VendorProduct
simple-helpsimplehelp

Affected versions

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

  • simple-help simplehelpbefore 5.5.16
  • simple-help simplehelp6.0

Versions reported by the vendor

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

  • SimpleHelp SimpleHelp

    • 5.5.0 and later · before 5.5.16affected · semver
    • 6.0 and later · before 6.0 RC2affected

Same product

simple-help: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-57727SimpleHelp remote support software v5.5.7 and before is vulnerable to multiple path traversal vulnerabilities that enable unauthenticated reKEV
    89Now
  • CVE-2024-57726SimpleHelp remote support software v5.5.7 and before has a vulnerability that allows low-privileges technicians to create API keys with exceKEV
    89Now
  • CVE-2024-57728SimpleHelp remote support software v5.5.7 and before allows admin users to upload arbitrary files anywhere on the file system by uploading aKEV
    77This week

Published before and after this one in the same product

  • ← EarlierCVE-2025-36727Jul 25, 2025 · SimpleHelp Inclusion of functionality from untrusted control sphere
    35Monitor
  • ← EarlierCVE-2025-36728Jul 25, 2025 · SimpleHelp Cross Site Request Forgery
    35Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
SimpleHelp SimpleHelp5.5.16Vendor (CNA)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1
  • Nuclei detection template ×1
  • 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
SourceKindDate
Metasploit moduleexploit/multi/http/simplehelp_oidc_auth_bypass_rceSimpleHelp OIDC Authentication Bypass Remote Code Executionexploit2026-06-12
Nuclei detection templateNuclei template CVE-2026-48558 —
Proof-of-concept repository on GitHubstars:82026-07-02

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.

  1. Metasploit-1 d
  2. Published
  3. CISA KEV+16 d
  4. First PoC+19 d
  5. TodayOct 28, 2026+138 d
EPSS, last 120 days+72% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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.

Variant candidates

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

No nightly-computed relations.

Chain candidates

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

—

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 user action 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
None
Scope
X

Weakness class (CWE)

CWE-347 · Improper Verification of Cryptographic Signature

CVSS vector

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

The verifier takes the algorithm to verify with from the token’s own header. Untrusted data ends up deciding its own verification rule.

The bug in code

The whole CWE-347 class

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

Vulnerable

ts
const claims = jwt.verify(token, publicKey);

Fixed

ts
const claims = jwt.verify(token, publicKey, {  algorithms: ["RS256"],  issuer: "https://id.example.com",  audience: "portal",});

Attack context

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

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records