PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT is_pem_format is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matching END marker. As a result, is_pem_format performs unbounded backtracking while searching for a PEM end marker. Consequently, an attacker can cause intensive CPU consumption. This issue is fixed in version 2.14.0.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-1333"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102270.json"
}{
"extracted_events": [
{
"cpe": "cpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "2.14.0"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "8b4e233a22206b34ec1186e912e75c0b2396ac07"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "2.14.0",
"range": [
{
"fixed": "c6fe464b356ff4b1ebc9ba62172d331a40aa27df"
}
],
"source": "REFERENCES_TAG"
}
]
}