# CVE-2026-103001 — jpadilla pyjwt

> As of 2026-09-30, CVE-2026-103001 is a MEDIUM-severity vulnerability in jpadilla pyjwt, CVSS v3.1 6.5, EPSS 0.3% (27.8th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-103001 as of 2026-09-30; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-09-30

## What is CVE-2026-103001?

PyJWT is a Python implementation of JSON Web Token standards. From 2.11.0 through 2.13.0, PyJWT's PyJWT._merge_options() method can modify a caller-supplied mutable options mapping when verify_signature is false. If an application reuses that same mapping for a later decode() or decode_complete() call and changes verify_signature to true, the mapping can retain false values for expiration, not-before, issued-at, audience, issuer, subject, and JWT ID checks. A signed token with invalid registered claims can then be accepted without disabling signature verification, but applications that create a fresh options mapping for each call are not affected.

The record classifies CVE-2026-103001 under weakness class [CWE-471](https://cwe.mitre.org/data/definitions/471.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on integrity. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 5 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 6.5 — MEDIUM (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N`)
- **EPSS (FIRST):** 0.3% probability of exploitation in the next 30 days, higher than 27.8% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-09-30

## Is CVE-2026-103001 being exploited?

It currently carries a trending score of 37 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **jpadilla**: pyjwt

Affected software packages:

- `pip:PyJWT`

## How to fix CVE-2026-103001

No vendor patch reference has been recorded for CVE-2026-103001 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-103001

No threat campaign in the Threadlinqs corpus currently references CVE-2026-103001, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-10-01.

**Vendor advisory and patch**

- [github.com](https://github.com/jpadilla/pyjwt/security/advisories/GHSA-gvp8-978c-rx2q)

**Other references**

- [github.com](https://github.com/jpadilla/pyjwt/issues/679)
- [github.com (0c87c8c8b1a74cac99ad8115f3050efcb7fbed35)](https://github.com/jpadilla/pyjwt/commit/0c87c8c8b1a74cac99ad8115f3050efcb7fbed35)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-103001
Full detection coverage and IOCs for threats exploiting CVE-2026-103001 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp