CVE-2023-26154 is a medium-severity (CVSS 5.9) CWE-331 vulnerability in pubnub. 1 public exploit reference exists, so weaponization risk is real. A fix is available for pubnub — see the affected versions and patch details below.
pubnub Insufficient Entropy vulnerability
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-26154 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
pubnub🐹github.com/pubnub/go/v7🐹github.com/pubnub/go🐹github.com/pubnub/go/v6🐹github.com/pubnub/go/v5☕com.pubnub:pubnub-kotlin☕com.pubnub:pubnub📦pubnub+6 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io, Go packages — download data is not available via public APIs for these ecosystems.
Description
Versions of the package pubnub before 7.4.0; all versions of the package com.pubnub:pubnub; versions of the package pubnub before 6.19.0; all versions of the package github.com/pubnub/go; versions of the package github.com/pubnub/go/v7 before 7.2.0; versions of the package pubnub before 7.3.0; versions of the package pubnub/pubnub before 6.1.0; versions of the package pubnub before 5.3.0; versions of the package pubnub before 0.4.0; versions of the package pubnub/c-core before 4.5.0; versions of the package com.pubnub:pubnub-kotlin before 7.7.0; versions of the package pubnub/swift before 6.2.0; versions of the package pubnub before 5.2.0; versions of the package pubnub before 4.3.0 are vulnerable to Insufficient Entropy via the getKey function, due to inefficient implementation of the AES-256-CBC cryptographic algorithm. The provided encrypt function is less secure when hex encoding and trimming are applied, leaving half of the bits in the key always the same for every encoded message or file.
Note:
In order to exploit this vulnerability, the attacker needs to invest resources in preparing the attack and brute-force the encryption.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | pubnub | all versions | 0.4.0cargo update -p pubnub --precise 0.4.0 |
| 🐹Go | github.com/pubnub/go/v7 | all versions | 7.2.0go get github.com/pubnub/go/v7@v7.2.0 |
| 🐹Go | github.com/pubnub/go | all versions | 0.0.0-20231016150651-428517fef5b9go get github.com/pubnub/go@v0.0.0-20231016150651-428517fef5b9 |
| 🐹Go | github.com/pubnub/go/v6 | all versions | 6.1.1-0.20231016150651-428517fef5b9go get github.com/pubnub/go/v6@v6.1.1-0.20231016150651-428517fef5b9 |
| 🐹Go | github.com/pubnub/go/v5 | all versions | 5.0.4-0.20231016150651-428517fef5b9go get github.com/pubnub/go/v5@v5.0.4-0.20231016150651-428517fef5b9 |
| ☕Maven | com.pubnub:pubnub-kotlin | all versions | 7.7.0com.pubnub:pubnub-kotlin:7.7.0 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pubnub, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pubnub to 0.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-26154 is resolved across your whole dependency graph.
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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-26154 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-26154. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-26154 in your dependencies?
O3 Security finds CVE-2023-26154 across crates.io, Go, Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.