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Fencer Vulns
low 2.2

CVE-2024-53861 json

Issuer field partial matches allowed in pyjwt

published 2024-11-29 23 mo ago modified 2026-09-10 1 mo ago also EUVD-2024-3440 , GHSA-75c5-xw7c-p5pm , PYSEC-2026-1814

cvss
2.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 57%
public exploits
0
none known

Summary

pyjwt is a JSON Web Token implementation in Python. An incorrect string comparison is run for `iss` checking, resulting in `"acb"` being accepted for `"_abc_"`. This is a bug introduced in version 2.10.0: checking the "iss" claim changed from `isinstance(issuer, list)` to `isinstance(issuer, Sequence)`. Since str is a Sequnce, but not a list, `in` is also used for string comparison. This results in `if "abc" not in "__abcd__":` being checked instead of `if "abc" != "__abc__":`. Signature checks are still present so real world impact is likely limited to denial of service scenarios. This issue has been patched in version 2.10.1. All users are advised to upgrade. There are no known workarounds for this vulnerability.

Patch / fix

  • pypi pyjwt 2.10.1
  • pyjwt_project pyjwt 2.10.1
  • python-PyJWT Linux Micro 6.1 2.12.1-slfo.1.1_1.1

suse advisories SUSE-SU-2026:20879-1

  • python-PyJWT openSUSE Tumbleweed 2.10.1-1.1

opensuse advisories openSUSE-SU-2024:14540-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-53861 updated cvss 2.2

pyjwt: Issuer field partial matches allowed in pyjwt

  • Red Hat OpenShift Lightspeed lightspeed-service-api-rhel9 Red Hat Ansible Automation Platform 1.2 ansible-tower Red Hat Ansible Automation Platform 2 python-pyjwt, python3x-pyjwt, python3.11-pyjwt, automation-controller, aap-cloud-metrics-collector-container, ansible-automation-platform-25/lightspeed-rhel8, +5 more Red Hat Enterprise Linux 9 fence-virt, fence-virtd, fence-agents, fence-virtd-cpg, fence-virtd-tcp, fence-agents-all, +51 more Red Hat Enterprise Linux 10 fence-agents-common Red Hat Quay 3 quay/quay-rhel8
    +2 more products
    Red Hat Satellite 6 python-pyjwt, python3-pyjwt Red Hat Update Infrastructure 4 for Cloud Providers python-pyjwt
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
23 mo ago

Exploit prediction

0.83% chance of exploitation in the next 30 days, higher than 57% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/jpadilla/pyjwt/security/advisories/GHSA-75c5-xw7c-p5pm referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 2.2 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N
GitHub 3.1 2.2 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 2.2 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N

Affected packages

ecosystem package affected fixed in
pypi pyjwt
>=2.10.0, <2.10.1
2.10.1

Affected products

  • jpadilla pyjwt
  • pyjwt_project pyjwt

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.