CVE-2020-28042

mediumpriority · track · 32EPSS 0.023 · 83 %ileexploit · PoCEURUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

1 exploit · PoC

Likely / severe?

2.33% (83rd) EPSS

CVSS 5 · medium

Is it mine?

4 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-27

ServiceStack before 5.9.2 mishandles JWT signature verification unless an application has a custom ValidateToken function that establishes a valid minimum length for a signature.

cvss

Technical severity, 0–10. One row per scoring source.

5.3

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.05mediumAV:N/AC:L/Au:N/C:N/I:P/A:Nprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 1.4

v3.15.3mediumAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:Nsecondary · FSTEC (BDU) RU

v3.15mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:Psecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-347USprimaryCWE-347USCWE-347US

exploits (1)

Public proof-of-concept and weaponised exploit code.

z-bool/Venom-JWT针对JWT渗透开发的漏洞验证/密钥爆破工具，针对CVE-2015-9235/空白密钥/未验证签名攻击/CVE-2016-10555/CVE-2018-0114/CVE-2020-28042的结果生成用于FUZZ，也可使用字典/字符枚举(包括JJWT)的方式进行爆破(JWT Crack)PoC · poc_in_github

affected products (4)

Products and version ranges known to be affected.

n/a n/a≤ n/aenisa_euvdEU
ServiceStack, Inc. ServiceStack≤ 5.9.1fstec_bduRU
servicestack servicestack< 5.9.2nvdUScpe:2.3:a:servicestack:servicestack:*:*:*:*:*:*:*:*
NuGet ServiceStack< 5.9.2osvUSpkg:nuget/ServiceStack

advisories (1)

Vendor and ecosystem advisories describing this.

GHSA-v5rv-hpxg-8x49Signature validation bypass in ServiceStack2021-01-13ghsa · osvUS
ServiceStack before 5.9.2 mishandles JWT signature verification unless an application has a custom ValidateToken function that establishes a valid minimum length for a signature.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd osv NVD CVE.org MITRE

published 2020-11-02modified 2026-06-17

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+1043 more

references (14)

External citations — patches, advisories, analysis.

scry

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