NIST deprecates RSA-2048 from 2030. Find every one of them before attackers do.
🐹
🐹 Go
Not in CISA KEV
CRITICAL severity

CVE-2016-9121 — square/go-jose.v1

CRITICALFix: square/go-jose@c758193

CVE-2016-9121 is a critical-severity (CVSS 9.1) CWE-326 vulnerability in gopkg.in/square/go-jose.v1. A fix is available for gopkg.in/square/go-jose.v1 — see the affected versions and patch details below.

Elliptic Curve Key Disclosure in go-jose

Also known asGHSA-86r9-39j9-99wpGO-2020-0010
Published
Updated
Affected
2 pkgs
Patched
2 / 2
Exploits
None indexed
Exploitation data as of Nov 2, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
1.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs73th percentile — riskier than 73% of all scored CVEsHighest risk
0.00%0.64%1.27%1.91%0.2%1.4%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected
🐹gopkg.in/square/go-jose.v1🐹github.com/square/go-jose

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

go-jose before 1.0.4 suffers from an invalid curve attack for the ECDH-ES algorithm. When deriving a shared key using ECDH-ES for an encrypted message, go-jose neglected to check that the received public key on a message is on the same curve as the static private key of the receiver, thus making it vulnerable to an invalid curve attack.

Affected Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogopkg.in/square/go-jose.v1all versions1.0.4go get gopkg.in/square/go-jose.v1@v1.0.4
🐹Gogithub.com/square/go-joseall versions1.0.4go get github.com/square/go-jose@v1.0.4

Affected Products

1 product · 1 configurations
Application
go-josego-jose_project
≤ 1.0.3
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gopkg.in/square/go-jose.v1, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update gopkg.in/square/go-jose.v1 to 1.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-9121 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

go-jose before 1.0.4 suffers from an invalid curve attack for the ECDH-ES algorithm. When deriving a shared key using ECDH-ES for an encrypted message, go-jose neglected to check that the received public key on a message is on the same curve as the static private key of the receiver, thus making it vulnerable to an invalid curve attack.
O3 Security · Impact-Aware SCA

Is CVE-2016-9121 in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works
CVE-2016-9121: square/go-jose.v1 — Fixed in 1.0.4