CVE-2026-32873 is a high-severity (CVSS 7.5) CWE-825 vulnerability in ewe. A fix is available for ewe — see the affected versions and patch details below.
ewe: Loop with Unreachable Exit Condition ('Infinite Loop')
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-32873.
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-2026-32873 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 377,166 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
eweReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Hex packages — download data is not available via public APIs for these ecosystems.
Description
ewe is a Gleam web server. Versions 0.8.0 through 3.0.4 contain a bug in the handle_trailers function where rejected trailer headers (forbidden or undeclared) cause an infinite loop. When handle_trailers encounters such a trailer, three code paths (lines 520, 523, 526) recurse with the original buffer (rest) instead of advancing past the rejected header (Buffer(header_rest, 0)), causing decoder.decode_packet to re-parse the same header on every iteration. The resulting loop has no timeout or escape — the BEAM process permanently wedges at 100% CPU. Any application that calls ewe.read_body on chunked requests is affected, and this is exploitable by any unauthenticated remote client before control returns to application code, making an application-level workaround impossible. This issue is fixed in version 3.0.5.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💧Hex | ewe | ≥ 0.8.0&&< 3.0.5 | 3.0.5mix deps.update ewe |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ewe, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ewe to 3.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-32873 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-2026-32873 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-32873. 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-2026-32873 in your dependencies?
O3 Security finds CVE-2026-32873 across Hex dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.