CVE Tools
Home/Vulnerability/CVE-2026-48524

CVE-2026-48524

PyJWT: PyJWKClient unbounded JWKS endpoint requests via attacker-controlled kid values (DoS)

Published: May 28, 2026Updated: May 28, 2026 Sources: CVE List
NVD MITRE
3.7CVSS
LOW

PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient.get_signing_key() forces a fresh HTTP request to the JWKS endpoint for every JWT with an unknown kid value, with no rate limiting. Since kid comes from the unverified token header, an attacker can trigger unlimited outbound requests. The vulnerability surfaces only when a JWKS fetch fails; an attacker can attempt to provoke that with sustained unknown-kid traffic, but the outcome depends on upstream JWKS-endpoint behavior (rate limiting, transient errors) which is beyond the attacker's control. This vulnerability is fixed in 2.13.0.

EPSS Score
N/A
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

CVSS Vector Breakdown

AV:NAC:HPR:NUI:NS:UC:NI:NA:L
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:LAvailability
Low

Weaknesses

CWE-460CWE-460: Improper Cleanup on Thrown ExceptionCWE-755CWE-755: Improper Handling of Exceptional Conditions

Affected Products

pyjwt
jpadilla

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

References

https://github.com/jpadilla/pyjwt/security/advisories/GHSA-fhv5-28vv-h8m8
github.com

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-48524 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
AI-powered analysis
Plain-language impact assessment and exploitation scenario
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows