CVE catalog
CVE-2026-48525
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 decod
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.37% · Oct 25, 2026
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 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. This vulnerability is fixed in 2.13.0.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | pyjwt | sid | 2.15.1-1 | fixed |
| Debian | pyjwt | forky | 2.15.1-1 | fixed |
| Debian | pyjwt | trixie | 2.10.1-2+deb13u1 | vulnerable |
| Debian | pyjwt | trixie-security | 2.10.1-2+deb13u1 | vulnerable |
| Debian | pyjwt | bookworm | 2.6.0-1+deb12u1 | vulnerable |
| Debian | pyjwt | bookworm-security | 2.6.0-1+deb12u1 | vulnerable |
| Cpe | pyjwt | Not reported | Not reported | vulnerable |
| Cpe | pyjwt | Not reported | Not reported | unknown |
| PyPI | pyjwt | Not reported | 2.13.0 | fixed |
| Ubuntu | pyjwt | noble | 2.7.0-1ubuntu0.2 | fixed |
| Ubuntu | python3-jwt | noble | 2.7.0-1ubuntu0.2 | fixed |
| Ubuntu | pyjwt | 24.04 | 2.7.0-1 | vulnerable |
| Ubuntu | pyjwt | 24.04 | 2.7.0-1ubuntu0.1 | vulnerable |
| Ubuntu | pyjwt | 24.04 | 2.7.0-1ubuntu0.2 | fixed |
| Ubuntu | pyjwt | 25.10 | 2.10.1-2 | vulnerable |
| Ubuntu | pyjwt | 25.10 | 2.10.1-2ubuntu0.1 | vulnerable |
| Ubuntu | pyjwt | 26.04 | 2.10.1-2 | vulnerable |
| Ubuntu | pyjwt | 26.04 | 2.10.1-3 | vulnerable |
| Ubuntu | pyjwt | 26.04 | 2.10.1-3build1 | vulnerable |
| Ubuntu | pyjwt | 26.04 | 2.10.1-4 | vulnerable |
| Ubuntu | pyjwt | 26.04 | 2.10.1-4ubuntu1 | vulnerable |
| Ubuntu | pyjwt | 26.04 | 2.10.1-4ubuntu1.1 | fixed |
| Cpe | pyjwt | Not reported | Not reported | unknown |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | pyjwt | source | sid | 2.13.0-1 | not yet assigned | Not reported | [1138191] |
| Debian | pyjwt | source | forky | 2.13.0-1 | not yet assigned | Not reported | [1138191] |
| Debian | pyjwt | source | trixie | (unfixed) | not yet assigned | Not reported | [1138191] |
| Debian | pyjwt | source | bookworm | (unfixed) | not yet assigned | Not reported | [1138191] |
| PyPI | pyjwt | PyPI | Not reported | 2.13.0 | Not reported | GHSA-W7VC-732C-9M39 | Not reported |
| Ubuntu | pyjwt | deb | noble | 2.7.0-1ubuntu0.2 | Not reported | Not reported | Not reported |
| Ubuntu | python3-jwt | deb | noble | 2.7.0-1ubuntu0.2 | Not reported | Not reported | Not reported |
| Ubuntu | pyjwt | deb | 24.04 | 2.7.0-1ubuntu0.2 | Not reported | UBUNTU-CVE-2026-48525 | Not reported |
| Ubuntu | pyjwt | deb | 26.04 | 2.10.1-4ubuntu1.1 | Not reported | UBUNTU-CVE-2026-48525 | Not reported |
Notes
[trixie] pyjwt: Minor issue [bookworm] pyjwt: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [python3-jwt]Affected
Source package: [pyjwt]
Details (4)
2.6.0-1+deb12u1· all · bookwormAffected
nvd · pyjwt · debian · bookworm; nvd · pyjwt · debian · 12
2.6.0-1+deb12u1· all · bookwormAffected
nvd · pyjwt · debian · bookworm; nvd · pyjwt · debian · 12
2.6.0-1+deb12u1· all · bookworm-securityAffected
nvd · pyjwt · debian · bookworm; nvd · pyjwt · debian · 12
2.6.0-1+deb12u1· all · bookworm-securityAffected
nvd · pyjwt · debian · bookworm; nvd · pyjwt · debian · 12
[Debian 13 (Trixie)]
- [python3-jwt]Affected
Source package: [pyjwt]
Details (4)
2.10.1-2+deb13u1· all · trixieAffected
nvd · pyjwt · debian · 13
2.10.1-2+deb13u1· all · trixieAffected
nvd · pyjwt · debian · 13
2.10.1-2+deb13u1· all · trixie-securityAffected
nvd · pyjwt · debian · 13
2.10.1-2+deb13u1· all · trixie-securityAffected
nvd · pyjwt · debian · 13
- [python-jwt-doc]Affected
Source package: [pyjwt]
Details (4)
2.10.1-2+deb13u1· all · trixieAffected
nvd · pyjwt · debian · 13
2.10.1-2+deb13u1· all · trixieAffected
nvd · pyjwt · debian · 13
2.10.1-2+deb13u1· all · trixie-securityAffected
nvd · pyjwt · debian · 13
2.10.1-2+deb13u1· all · trixie-securityAffected
nvd · pyjwt · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/]
- [https://github.com/jpadilla/pyjwt/security/advisories/GHSA-w7vc-732c-9m39]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-48525]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-48525]
- [https://osv.dev/vulnerability/GHSA-w7vc-732c-9m39]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-48525]
- [https://security-tracker.debian.org/tracker/CVE-2026-48525]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48525.json]
- [https://ubuntu.com/security/notices/USN-8823-1]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]