CVE-2026-79575Public exploitNetwork attack vector

Authentication bypass via predictable JWT signing secret

Published Sep 8, 2026 · Updated Sep 9, 2026

Authentication bypass in yfexam-exam 2.0 allows remote attackers to impersonate users by forging JWTs with a predictable signing secret. JwtUtils.encryptSecret derives the HMAC key from the token's unverified username and a 12-value calendar month instead of a random server-side secret. A reachable API and a known or guessable username suffice; the demonstrated default administrator account exposes protected account data without a password.

CVSS severity7.5
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in yfexam-exam 2.0 allows remote attackers to impersonate users by forging JWTs with a predictable signing secret. JwtUtils.encryptSecret derives the HMAC key from the token's unverified username and a 12-value calendar month instead of a random server-side secret. A reachable API and a known or guessable username suffice; the demonstrated default administrator account exposes protected account data without a password.

The record

CVE
CVE-2026-79575
Published
Sep 8, 2026
Updated
Sep 9, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-330, T1550.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5CISA ADP VulnrichmentCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-330Use of Insufficiently Random Values
T1550.001Application Access Token

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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