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CVE-2026-48526Proof of concept (PoC) published · CISA

PyJWT: Public-key JWK accepted as HMAC secret enables forged HS256 tokens when mixed families are allowed

CVSS score

7.4

EPSS probability

%0.4

Risk score

0.0

Published

4 mo ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Official patch verified

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Impact on My Inventory

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Vulnerability description

DayBreach CVE AI Research

CVE-2026-48526 has vendor, distribution, patch and security-source records on file. We can compare them and prepare an explanation linked to the evidence.

PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, when the verifier is decoding JSON Web Tokens, while supporting both asymmetric and HMAC algorithms, the library does not validate use of JSON Web Keys in HMAC algorithm, allowing attacker to use the issuer public key as the secret key for HMAC algorithm. This vulnerability is fixed in 2.13.0.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-48526 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1jpadillapyjwt View
2pyjwt projectpyjwt View
Total affected vendors: 2|Products: 2

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
7.4CVSS V3_1HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NCVE CNA
7.4CVSS V3_1HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NCVE ADP
7.4CVSS V31HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NNVD
7.4CVSS 3.x—CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NMicrosoft MSRC

Patch and Remediation Guide

Solution & Remediation Advisory

Patch verified

1 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

reference

Yama veya çözüm referansı

Open source
Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Apply the official update named in the evidence only to the matching product and version.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-48526 is associated with the following CWEs:

CWE-287: Improper AuthenticationCWE-347: Common Weakness Enumeration Entry CWE-347

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-48526 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsGerekmiyor
UserGerekmiyor

Official Sources and Advisories

https://github.com/jpadilla/pyjwt/security/advisories/GHSA-xgmm-8j9v-c9wxvendor-advisoryhttps://access.redhat.com/errata/RHSA-2026:25902nvdhttps://access.redhat.com/errata/RHSA-2026:25928nvdhttps://access.redhat.com/errata/RHSA-2026:26206nvdhttps://access.redhat.com/errata/RHSA-2026:28571nvdhttps://access.redhat.com/errata/RHSA-2026:30076nvdhttps://access.redhat.com/errata/RHSA-2026:30088nvdhttps://access.redhat.com/errata/RHSA-2026:30089nvdhttps://access.redhat.com/errata/RHSA-2026:33683nvdhttps://access.redhat.com/errata/RHSA-2026:34160nvd

CVSS Vector Radar Chart

7.4 / 10
Attack VectorNetworkComplexityHighPrivilegesNoneUser Interact.NoneConfidentialityHighIntegrityNoneAvailabilityNone

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone required
User InteractionNone required
Confidentiality (Gizlilik)High
Integrity (Bütünlük)None
Availability (Erişilebilirlik)None

Yama doğrulandı

1 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

Follow the vendor

J
jpadilla logo
jpadilla
PP
pyjwt project logo
pyjwt project

Weakness Type (CWE & CAPEC)

CWE-287 CWE-347

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