CVE-2026-27932

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Source
https://cve.org/CVERecord?id=CVE-2026-27932
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-27932.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-27932
Aliases
Downstream
Related
Published
2026-03-03T22:48:21.306Z
Modified
2026-04-10T05:37:34.779578Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
joserfc PBES2 p2c Unbounded Iteration Count enables Denial of Service (DoS)
Details

joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. In 1.6.2 and earlier, a resource exhaustion vulnerability in joserfc allows an unauthenticated attacker to cause a Denial of Service (DoS) via CPU exhaustion. When the library decrypts a JSON Web Encryption (JWE) token using Password-Based Encryption (PBES2) algorithms, it reads the p2c (PBES2 Count) parameter directly from the token's protected header. This parameter defines the number of iterations for the PBKDF2 key derivation function. Because joserfc does not validate or bound this value, an attacker can specify an extremely large iteration count (e.g., 2^31 - 1), forcing the server to expend massive CPU resources processing a single token. This vulnerability exists at the JWA layer and impacts all high-level JWE and JWT decryption interfaces if PBES2 algorithms are allowed by the application's policy.

Database specific 
{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27932.json",
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-770"
    ]
}
References

Affected packages

Git / github.com/authlib/joserfc

Affected ranges

Type
GIT
Repo
https://github.com/authlib/joserfc
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
696a9611ab982c45ee2190ed79ca8e1d8e09398f

Affected versions

0.*
0.10.0
0.11.0
0.11.1
0.12.0
0.2.0
0.3.0
0.4.0
0.5.0
0.6.0
0.7.0
0.8.0
0.9.0
1.*
1.0.0
1.0.1
1.0.2
1.0.3
1.0.4
1.1.0
1.2.0
1.2.1
1.2.2
1.3.0
1.3.1
1.3.2
1.3.3
1.4.0
1.4.1
1.4.3
1.5.0
1.6.0
1.6.1
1.6.2

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-27932.json"