What is CVE-2015-2951?

CVE-2015-2951 is a vulnerability in F21 Jwt, classified under Improper Input Validation. Published 2015-06-05.

Is CVE-2015-2951 known to be exploited?

12 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Improper input validation in F21 Jwt

CVE-2015-2951

JWT.php in F21 JWT before 2.0 allows remote attackers to bypass signature verification via crafted tokens.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2015-06-05 · last modified 2026-06-17.

CVSS v2 metric

CVSS v2 base score 5.0 (Medium). Vector: AV:N/AC:L/Au:N/C:N/I:P/A:N. This CVE predates CVSS v3 and has no v3 score from NVD.

EPSS exploit prediction

EPSS: 0.037 (89.5th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 90th percentile — 89.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.038 · newest: 0.037 · change: -0.000

Affected products

F21 Jwt

Weakness classification (CWE)

CWE-20 — Improper Input Validation

Public proof-of-concept exploits

References

jvn.jp/en/jp/JVN06120222/index.html (Vendor Advisory, third-party-advisory)
www.securityfocus.com/bid/75021 (vdb-entry)
jvndb.jvn.jp/jvndb/JVNDB-2015-000073 (Vendor Advisory, third-party-advisory)
github.com/F21/jwt/commit/a327cf9052df8f9f97728ca0b5fa78a8231b79b6

Frequently asked questions

What is CVE-2015-2951?: CVE-2015-2951 is a vulnerability in F21 Jwt, classified under Improper Input Validation. Published 2015-06-05.
Is CVE-2015-2951 known to be exploited?: 12 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.