Is there a public exploit for CVE-2026-48525?

No public exploit for CVE-2026-48525 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-48525?

CVE-2026-48525 scores CVSS 5.3 (v3.1), rated medium. EPSS puts the chance of exploitation in the next 30 days at 0.37%.

What does CVE-2026-48525 affect?

CVE-2026-48525 affects jpadilla pyjwt.

5.3 Medium

PyJWT is a JSON Web Token implementation in Python.

CVE-2026-48525

[!NOTE] Practical impact depends on whether request body-size limits are enforced upstream (proxy/web-server/framework). Deployments with typical body-size caps (≤2 MB) bound the amplifier significantly; deployments accepting larger token inputs are more exposed. When verifying detached JWS tokens using the unencoded-payload option ("b64": false, RFC 7797), PyJWT performs Base64URL decoding of the compact-serialization payload segment before enforcing the detached-payload rules. For b64=false, PyJWT later discards that decoded payload and replaces it with the caller-provided detachedpayload. In practice, this turns the middle segment into an attacker-controlled “work amplifier”: a remote client can supply an arbitrarily large Base64URL payload segment that forces CPU work + memory allocations even if the signature is invalid. This creates an unauthenticated DoS vector against any endpoint that verifies detached JWS using PyJWT. Affected Component(s) jwt/apijws.py PyJWS.decode() / PyJWS.decodecomplete() load() (parsing and Base64URL decoding) Root Cause (exact logic flaw) What happens in the code In jwt/apijws.py, decodecomplete() does the following (order matters): Calls load(jwt)…

Assessment

CVSS: 5.3 (v3.1)
Severity: Medium
EPSS: 0.37% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 28 May 2026
Last updated: 25 October 2026
Affected: jpadilla · pyjwt · pyjwt
Weakness: CWE-400
Assigner: security-advisories@github.com

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

At the source

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