GHSA-7432-952r-cw78: authlib (CVE-2026-28490)

Package	Ecosystem	Affected	Fixed in
authlib	PyPI	<1.6.9	1.6.9

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Authlib versions before 1.6.9 are affected by a padding oracle in JWE decryption with the RSA1_5 key management algorithm, which Authlib enables in its default registry. The source describes a differing exception between invalid padding and invalid authentication tags that could let an attacker who can send many JWE tokens to a decrypting endpoint recover the content encryption key and decrypt or forge tokens. The source gives limited detail on the exact attacker conditions and the full impact. Upgrade to Authlib 1.6.9 or later.

Written 6 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
8.3	High	4.0	CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0016, the 4th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 15:04 UTC First seen by agentprime
31 Oct 2026, 15:04 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.