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QSN-8823-1: PyJWT vulnerabilities

September 25, 2026

Summary

Several security issues were fixed in PyJWT.

Details

It was discovered that PyJWT incorrectly handled certain URIs when using PyJWKClient. A remote attacker could possibly use this issue to perform server-side request forgery (SSRF) or expose sensitive local files. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-48522)

It was discovered that PyJWT incorrectly verified cryptographic signatures when decoding tokens with PyJWK keys. A remote attacker could possibly use this issue to bypass signature verification and forge valid JSON Web Tokens. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-48523)

It was discovered that PyJWT incorrectly handled unknown key identifiers in PyJWKClient. A remote attacker could possibly use this issue to cause PyJWT to make excessive network requests, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-48524)

It was discovered that PyJWT incorrectly handled payload decoding during detached JWS token verification. A remote attacker could possibly use this issue to cause PyJWT to consume excessive resources, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-48525)

It was discovered that PyJWT incorrectly validated JSON Web Keys when decoding tokens with both HMAC and asymmetric algorithms enabled. A remote attacker could possibly use this issue to forge valid tokens, resulting in an authentication bypass. (CVE-2026-48526)

Affected QuantaStor releases

ReleasePlatformPackageExposureShipped versionFixed versionStatus
6.9.1.001Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.62.3.0-1ubuntu0.4Fixed in this release
6.9.0.464Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.52.3.0-1ubuntu0.4Fixed in this release
6.8.6.015Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.4Fixed by QuantaStor security update
6.8.5.018Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.4Fixed by QuantaStor security update
6.8.4.038Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.4Fixed by QuantaStor security update
6.8.3.018Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.4Fixed by QuantaStor security update
6.8.2.002Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.4Fixed by QuantaStor security update
6.8.1.007Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.4Fixed by QuantaStor security update
6.8.0.205Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.4Fixed by QuantaStor security update

Internally-facing: only accessible when logged into the QuantaStor console/ssh as the qadmin administrative sudo user; generally lower priority. Externally-facing: part of a service the storage platform presents on the network (or the kernel), so potentially reachable over the network.

CVEs

CVE-2026-48524, CVE-2026-48526, CVE-2026-48525, CVE-2026-48523, CVE-2026-48522

References

https://ubuntu.com/security/notices/USN-8823-1

https://nvd.nist.gov/vuln/detail/CVE-2026-48524

https://nvd.nist.gov/vuln/detail/CVE-2026-48526

https://nvd.nist.gov/vuln/detail/CVE-2026-48525

https://nvd.nist.gov/vuln/detail/CVE-2026-48523

https://nvd.nist.gov/vuln/detail/CVE-2026-48522

Update

Fixes marked Fixed by QuantaStor security update are applied by upgrading QuantaStor with security patches included (Upgrade Manager). Fixed package versions:

PlatformPackageVersion
bionicpyjwt1.5.3+ds1-1ubuntu0.1+esm2
Ubuntu 20.04 LTSpyjwt1.7.1-2ubuntu2.1+esm2
Ubuntu 22.04 LTSpyjwt2.3.0-1ubuntu0.4
Ubuntu 24.04 LTSpyjwt2.7.0-1ubuntu0.2
resolutepyjwt2.10.1-4ubuntu1.1
xenialpyjwt1.3.0-1ubuntu0.1+esm2