CVE-2026-119283 · GHSA-jpxq-7h8p-2q76

joserfc: Unbounded JWE General JSON `recipients` Array Leads to CPU Exhaustion (DoS) via Repeated RSA Private-Key Decryption

Risk score: 55/100
CVSS: 7.5 v3.1
Published: 29 Oct 2026

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What to know

What it is: joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.7.5, joserfc.jwe.decrypt_json() accepts a JWE General JSON Serialization recipients array without a count limit and calls decrypt_cek() for every entry. An unauthenticated attacker who…
Affected: joserfc (pip) < 1.7.5
Fix: Upgrade joserfc to 1.7.5 or later.
Exploitation: No known exploitation

Story map

Story map: the flaws, the fix, how it unfolded and what it connects to. Boxes link to the record or article.

At a glance

joserfc: Yellow, plan it in. joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.7.5, joserfc.jwe.decrypt_json() accepts a JWE General JSON Serialization recipients array without a count limit and calls decrypt_cek() for every entry. An unauthenticated attacker who…

The flaws

CVE-2026-119283: Unbounded JWE General JSON `recipients` Array Leads to CPU Exhaustion (DoS) via Repeated RSA Private-Key Decryption (CVSS 7.5)
CVE-2026-119284: Compact JWS size guard allocates attacker-controlled segments before rejection (CVSS 6.9)

The fix

Upgrade joserfc: 1.7.5 · 1.7.6 or later on your release line

Who is exposed: joserfc (pip) < 1.7.5

Where it stands

No known exploitation

Connects to

Same weakness: Denial of service (CWE-400). 301 other warnings in 30 days

Why it is Yellow

CVSS 7.5 high
Remotely exploitable without logging in
On your watchlist: PyPI

Affected packages

Package	Ecosystem	Vulnerable	Fixed in
joserfc	pip	< 1.7.5	1.7.5

References

Original description

joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.7.5, joserfc.jwe.decrypt_json() accepts a JWE General JSON Serialization recipients array without a count limit and calls decrypt_cek() for every entry. An unauthenticated attacker who can submit a JWE to an endpoint using an RSA key-management algorithm can choose the number of private-key decryption operations performed by one request. The verify_all_recipients option does not reduce this work because the affected loop processes every recipient before consulting that setting, allowing repeated requests to exhaust service CPU without affecting confidentiality or integrity. This issue is fixed in version 1.7.5.

Last activity 30 Oct 2026. Patch Forecast updates every hour.