How severe is CVE-2020-35918?

CVE-2020-35918 has a CVSS score of 5.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2020-35918?

CVE-2020-35918 affects the following packages: branca (crates.io). Ecosystems affected: crates.io.

How do I fix CVE-2020-35918?

Update branca to 0.10.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-35918 is resolved across your whole dependency graph.

How do I detect CVE-2020-35918 in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for branca. 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-2020-35918 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-2020-35918?

O3 pinpoints whether CVE-2020-35918 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-2020-35918 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2020-35918, including 2 in-the-wild exploitations 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.

When was CVE-2020-35918 published, and has it been updated?

CVE-2020-35918 was published on December 31, 2020 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀

🦀 crates.io

Not in CISA KEV

MEDIUM severity

CVE-2020-35918

MEDIUM

CVE-2020-35918 is a medium-severity (CVSS 5.5) vulnerability in branca. 2 public exploit references exist, so weaponization risk is real. O3 Security confirms whether CVE-2020-35918 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Unexpected panic when decoding tokens in branca

Also known asGHSA-c9rv-3jmq-527wRUSTSEC-2020-0075

Published

Dec 31, 2020

Updated

Jul 8, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

2 known

Exploitation data as of Jul 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🦀branca

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

Description

An issue was discovered in the branca crate before 0.10.0 for Rust. Decoding tokens (with invalid base62 data) can panic.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`branca`	all versions	0.10.0

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.

An issue was discovered in the branca crate before 0.10.0 for Rust. Deco…

rustsec.orgNVDJan 2021

An issue was discovered in the branca crate before 0.10.0 for Rust. Deco…

github.comNVDSep 2022

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for branca. 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 branca to 0.10.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-35918 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-2020-35918 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-2020-35918. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

An issue was discovered in the branca crate before 0.10.0 for Rust. Decoding tokens (with invalid base62 data) can panic.

O3 Security · Impact-Aware SCA

Is CVE-2020-35918 in your dependencies?

O3 detects CVE-2020-35918 across crates.io 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