CVE-2026-48525: PyJWT is a JSON Web Token implementation in Python

This week

MEDIUM 5.3REMOTEUPGRADE

CVE-2026-48525 is a medium-severity flaw (CVSS 5.3) affecting pyjwt. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

PyJWT is a JSON Web Token implementation in Python. From 2.8.0 to 2.12.1, 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 detached_payload. In practice, this turns the middle segme

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 69%)
CISA exploited list	No
Weakness	CWE-400
Published	2026-05-28
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: pyjwt project

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-28 16:16 UTCPublished CVE record published
2026-10-25 23:10 UTCUpdated Record last modified

pyjwt project pyjwt UPGRADE

Affected: >= 2.8.0 and <= 2.12.1

Fixed in: newer than 2.12.1

Safe to downgrade to: a release before 2.8.0

1. Check installed version

apt-cache policy pyjwt || rpm -q pyjwt || pyjwt --version

2. UPGRADE to newer than 2.12.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade pyjwt

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade pyjwt

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 2.8.0 (Debian / Ubuntu)

apt-cache madison pyjwt sudo apt install pyjwt=<VERSION_BEFORE_2.8.0> sudo apt-mark hold pyjwt

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list pyjwt sudo dnf downgrade pyjwt-<VERSION_BEFORE_2.8.0> sudo dnf versionlock add pyjwt

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-48525?

pyjwt: upgrade to newer than 2.12.1. Exact commands for each OS are on this page.

Is CVE-2026-48525 being exploited?

CVE-2026-48525 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-48525 affect?

CVE-2026-48525 affects pyjwt. Severity is medium (CVSS 5.3). PyJWT is a JSON Web Token implementation in Python. From 2.8.0 to 2.12.1, when verifying detached JWS tokens using the unencoded-payload option ("b64": false, RFC 7797), PyJWT performs Base64URL decoding of the compact-serialization payload

How urgent is CVE-2026-48525?

Priority 36/100. Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Python vulnerabilities

Related CVEs

CVE-2026-48523 MEDIUM 5.4 UPGRADE PyJWT is a JSON Web Token implementation in Python

References

← Back to latest CVEs