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QSN-8916-1: PyJWT vulnerabilities

October 13, 2026

Summary

Several security issues were fixed in PyJWT.

Details

YuSung Han discovered that PyJWT did not properly validate certain JWK keys when performing HMAC verification. An attacker could possibly use this issue to forge authentication tokens. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-102266)

Rohan Das discovered that PyJWT incorrectly handled redirects when fetching key sets. A remote attacker could possibly use this issue to cause PyJWT to disclose sensitive information. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 26.04 LTS. (CVE-2026-102267)

It was discovered that PyJWT incorrectly recognized certain PEM representations. An attacker who knew the public key could possibly use this issue to forge authentication tokens. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 26.04 LTS. (CVE-2026-102268)

Nuno Lopes discovered that PyJWT incorrectly handled DER public keys when performing HMAC verification. An attacker who knew the public key could possibly use this issue to forge authentication tokens. (CVE-2026-102271)

It was discovered that PyJWT did not properly handle certain JWK keys prefixed with a byte-order mark. An attacker who knew the public key could possibly use this issue to forge authentication tokens. (CVE-2026-102272)

Charles Vosburgh discovered that PyJWT incorrectly handled certain JWK containers when performing HMAC verification. An attacker who knew the public key could possibly use this issue to forge authentication tokens. (CVE-2026-102273)

Affected QuantaStor releases

ReleasePlatformPackageExposureShipped versionFixed versionStatus
6.9.1.001Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.62.3.0-1ubuntu0.5Fixed in this release
6.9.0.464Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.52.3.0-1ubuntu0.5Fixed in this release
6.8.6.015Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.5Fixed by QuantaStor security update
6.8.5.018Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.5Fixed by QuantaStor security update
6.8.4.038Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.5Fixed by QuantaStor security update
6.8.3.018Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.5Fixed by QuantaStor security update
6.8.2.002Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.5Fixed by QuantaStor security update
6.8.1.007Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.5Fixed by QuantaStor security update
6.8.0.205Ubuntu 22.04 LTSpython3-jwtExternally-facing2.3.0-1ubuntu0.32.3.0-1ubuntu0.5Fixed 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-2026-102267, CVE-2026-102268, CVE-2026-102271, CVE-2026-102266, CVE-2026-102273, CVE-2026-102272

References

https://ubuntu.com/security/notices/USN-8916-1

https://nvd.nist.gov/vuln/detail/CVE-2026-102267

https://nvd.nist.gov/vuln/detail/CVE-2026-102268

https://nvd.nist.gov/vuln/detail/CVE-2026-102271

https://nvd.nist.gov/vuln/detail/CVE-2026-102266

https://nvd.nist.gov/vuln/detail/CVE-2026-102273

https://nvd.nist.gov/vuln/detail/CVE-2026-102272

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+esm3
Ubuntu 20.04 LTSpyjwt1.7.1-2ubuntu2.1+esm3
Ubuntu 22.04 LTSpyjwt2.3.0-1ubuntu0.5
Ubuntu 24.04 LTSpyjwt2.7.0-1ubuntu0.3
resolutepyjwt2.10.1-4ubuntu1.2
xenialpyjwt1.3.0-1ubuntu0.1+esm3