How severe is CVE-2023-23626?

CVE-2023-23626 has a CVSS score of 5.9/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-23626?

CVE-2023-23626 affects the following packages: github.com/ipfs/go-bitfield (Go). Ecosystems affected: Go.

How do I fix CVE-2023-23626?

Update github.com/ipfs/go-bitfield to 1.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-23626 is resolved across your whole dependency graph.

How do I detect CVE-2023-23626 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/ipfs/go-bitfield. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2023-23626 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2023-23626?

O3 pinpoints whether CVE-2023-23626 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2023-23626 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2023-23626, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2023-23626?

CVE-2023-23626 has an EPSS (Exploit Prediction Scoring System) score of 0.9%, placing it in the 55th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2023-23626 published, and has it been updated?

CVE-2023-23626 was published on February 9, 2023 and was last updated on April 2, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

CVE-2023-23626

MEDIUM

Denial of service when feeding malformed size arguments in go-bitfield

Also known asGHSA-2h6c-j3gf-xp9rGO-2023-1558

Published

Feb 9, 2023

Updated

Apr 2, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

0.9%probability of exploitation in next 30 days

Lower Risk55th percentile+0.44%

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.

Blast Radius

1 pkg affected

🐹github.com/ipfs/go-bitfield

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-bitfield is a simple bitfield package for the go language aiming to be more performant that the standard library. When feeding untrusted user input into the size parameter of NewBitfield and FromBytes functions, an attacker can trigger panics. This happen when the size is a not a multiple of 8 or is negative. There were already a note in the NewBitfield documentation, however known users of this package are subject to this issue. Users are advised to upgrade. Users unable to upgrade should ensure that size is a multiple of 8 before calling NewBitfield or FromBytes.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/ipfs/go-bitfield`	all versions	1.1.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

go-bitfield is a simple bitfield package for the go language aiming to b…

github.comNVDFeb 2023

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/ipfs/go-bitfield. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/ipfs/go-bitfield to 1.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-23626 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 pinpoints whether CVE-2023-23626 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2023-23626. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

go-bitfield is a simple bitfield package for the go language aiming to be more performant that the standard library. When feeding untrusted user input into the size parameter of `NewBitfield` and `FromBytes` functions, an attacker can trigger `panic`s. This happen when the `size` is a not a multiple of `8` or is negative. There were already a note in the `NewBitfield` documentation, however known users of this package are subject to this issue. Users are advised to upgrade. Users unable to upgrade should ensure that `size` is a multiple of 8 before calling `NewBitfield` or `FromBytes`.

O3 Security · Impact-Aware SCA

Is CVE-2023-23626 in your dependencies?

O3 detects CVE-2023-23626 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works