CVE-2026-48525Public exploitNetwork attack vectorHinoki check available

Unauthenticated DoS via unused payload decoding

Published May 28, 2026 · Updated May 28, 2026

Uncontrolled resource consumption in PyJWT 2.8.0 through 2.12.1 allows remote attackers to interrupt services via crafted detached JWS tokens. In jwt/api_jws.py, PyJWS.decode_complete() calls _load(), which Base64URL-decodes an attacker-sized compact payload segment before b64=false handling discards it for detached_payload. Exposure requires an endpoint that accepts tokens for b64=false detached-JWS verification; upstream request-size limits bound the CPU and memory cost.

CVSS severity5.3
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Uncontrolled resource consumption in PyJWT 2.8.0 through 2.12.1 allows remote attackers to interrupt services via crafted detached JWS tokens. In jwt/api_jws.py, PyJWS.decode_complete() calls _load(), which Base64URL-decodes an attacker-sized compact payload segment before b64=false handling discards it for detached_payload. Exposure requires an endpoint that accepts tokens for b64=false detached-JWS verification; upstream request-size limits bound the CPU and memory cost.

The record

CVE
CVE-2026-48525
Published
May 28, 2026
Updated
May 28, 2026
Vendor
Jose Padilla
Product
PyJWT
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 28, 2026CVE publishedPublication date reported by the CVE source.
  2. May 28, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 2.8.0, < 2.13.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Jose Padilla · PyJWTversion=>= 2.8.0, < 2.13.0

Published CVSS scores

5.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

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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