Security readout for executives and security teams
Plain-English summary
A specific PyJWT verification path can waste server CPU and memory before rejecting a bad token. Only systems that verify detached JWS tokens with the b64=false option are indicated as exposed. The issue can be triggered remotely without authentication and mainly affects availability, not data confidentiality or integrity.
Executive priority
Treat as a targeted availability risk. It is not a broad data breach indicator, but exposed authentication or integration endpoints could be degraded cheaply if they use this uncommon detached JWS mode. Patch affected services during the next urgent maintenance window.
Technical view
PyJWT versions 2.8.0 through 2.12.1 Base64URL-decode the compact JWS payload segment before enforcing detached-payload handling for b64=false. That decoded value is later discarded and replaced by caller-supplied detached_payload, creating unbounded work and allocation on attacker-controlled input. Fixed in PyJWT 2.13.0.
Likely exposure
Exposure appears limited to Python services using PyJWT 2.8.0 to before 2.13.0 and verifying detached JWS tokens with RFC 7797 b64=false. Ordinary JWT/JWS use is not identified as affected in the supplied sources.
Exploitation context
The source bundle describes an unauthenticated network DoS vector with low attack complexity. KEV is false, and the supplied sources do not cite active exploitation or public exploit use. Evidence supports availability impact only, rated CVSS 5.3 medium.
Researcher notes
The important exposure condition is behavioral, not just package version. Confirm whether the application verifies compact detached JWS using b64=false. The root issue is premature Base64URL decoding of an unused payload segment before detached-payload replacement and signature failure handling.
Mitigation direction
- Upgrade PyJWT to version 2.13.0 or later.
- Rebuild and redeploy services that bundle vulnerable PyJWT versions.
- Prioritize endpoints that verify detached JWS tokens with b64=false.
- If upgrade is delayed, review the vendor advisory for supported guidance.
- Keep existing request-size and rate controls around token-verification paths.
Validation and detection
- Inventory Python dependencies for PyJWT versions 2.8.0 through 2.12.1.
- Search application code for detached_payload and b64=false verification flows.
- Confirm production runtime images use PyJWT 2.13.0 or later.
- Review externally reachable routes that perform JWS verification.
- Monitor affected services for CPU, memory, and error spikes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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Open ATT&CK lookupCredential and access behavior lookup
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Open ATT&CK lookupCVE-2026-48525 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L3.91.4GitHub_MVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-w7vc-732c-9m39CVE reference, GitHub_M · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.