CVE-2017-11424

mediumpriority · track · 31OT risk · elevatedEPSS 0.018 · 78 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.80% (78th) EPSS

CVSS 5 · medium

Is it mine?

5 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-27

In PyJWT 1.5.0 and below the `invalid_strings` check in `HMACAlgorithm.prepare_key` does not account for all PEM encoded public keys. Specifically, the PKCS1 PEM encoded format would be allowed because it is prefaced with the string `-----BEGIN RSA PUBLIC KEY-----` which is not accounted for. This enables symmetric/asymmetric key confusion attacks against users using the PKCS1 PEM encoded public keys, which would allow an attacker to craft JWTs from scratch.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:P/A:Nprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.07.5highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.07.5highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nsecondary · OSV

v3.06.9mediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-327USLLM-inferred

affected products (5)

Products and version ranges known to be affected.

n/a n/a≤ n/aenisa_euvdEU
debian debian linux= 8.0nvdUScpe:2.3:o:debian:debian_linux:*:*:*:*:*:*:*:*
debian debian linux= 9.0nvdUScpe:2.3:o:debian:debian_linux:*:*:*:*:*:*:*:*
pyjwt project pyjwt≤ 1.5.0nvdUScpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:*
PyPI pyjwt< 1.5.1osvUSpkg:pypi/pyjwt

advisories (2)

Vendor and ecosystem advisories describing this.

GHSA-r9jw-mwhq-wp62PyJWT vulnerable to key confusion attacks2022-05-13ghsa · osvUS
In PyJWT 1.5.0 and below the `invalid_strings` check in `HMACAlgorithm.prepare_key` does not account for all PEM encoded public keys. Specifically, the PKCS1 PEM encoded format would be allowed because it is prefaced with the string `-----BEGIN RSA PUBLIC KEY-----` which is not accounted for. This enables symmetric/asymmetric key confusion attacks against users using the PKCS1 PEM encoded public keys, which would allow an attacker to craft JWTs from scratch.
PYSEC-2017-242017-08-24vendor · osvUS
In PyJWT 1.5.0 and below the `invalid_strings` check in `HMACAlgorithm.prepare_key` does not account for all PEM encoded public keys. Specifically, the PKCS1 PEM encoded format would be allowed because it is prefaced with the string `-----BEGIN RSA PUBLIC KEY-----` which is not accounted for. This enables symmetric/asymmetric key confusion attacks against users using the PKCS1 PEM encoded public keys, which would allow an attacker to craft JWTs from scratch.

also known as (6)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv nvd NVD CVE.org MITRE

published 2017-08-24modified 2026-06-17

references (8)

External citations — patches, advisories, analysis.

http://www.debian.org/security/2017/dsa-3979 cnnvd
https://github.com/jpadilla/pyjwt/pull/277 cnnvd
https://github.com/jpadilla/pyjwt/pull/277/commitsPatchcnnvd
https://www.debian.org/security/2017/dsa-3979 cnnvd
http://www.debian.org/security/2017/dsa-3979 enisa_euvd
https://github.com/jpadilla/pyjwt/pull/277 enisa_euvd
http://www.debian.org/security/2017/dsa-3979Third Party Advisorynvd
https://github.com/jpadilla/pyjwt/pull/277Issue TrackingPatchThird Party Advisorynvd

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