CVE-2026-32686 — Unbounded exponent in decimal enables unauthenticated DoS
Uncontrolled Resource Consumption vulnerability in ericmj decimal allows unauthenticated remote Denial of Service. The decimal library does not bound the exponent on parsed input. Storing a decimal with a very large exponent (e.g. Decimal.new("1e1000000000")) is accepted without error. Subsequent calls to arithmetic functions (Decimal.add/2, Decimal.sub/2, Decimal.div/2M), Decimal.to_string/2M with :normalM or :xsdM format, Decimal.to_integer/1M, Decimal.round/3M, or Decimal.compare/3M with a threshold allocate memory proportional to the exponent value, which can exhaust available memory and crash the BEAM VM. Any application that accepts user-supplied decimal input and subsequently performs arithmetic, rounding, conversion to integer, or string formatting on it is exposed. A single malicious request is sufficient to cause an out-of-memory crash. This issue affects decimal: from 0.1.0 before 3.0.0.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.3% (30-day exploitation probability)+4
- Technical severity (medium)+3
- CISA SSVC: exploitation "poc"+5
- Automatable exploitation (SSVC)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Erlang Decimal: fixed in version 3.0.0 — github.com (GitHub Security Advisories)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Ericmj Decimal, Erlang Decimal).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 6.9 | CVSS 4.0 | Medium | — | — | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db via NIST National Vulnerability Database |
| 6.9 | CVSS 4.0 | Medium | — | — | EEF via CVE Program (cve.org) e CISA ADP |
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (score shown at the top: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.34%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Fix documented
- Affected products added · erlang/decimal
- Affected products added · ericmj/decimal
- SSVC assessment updated
- Record published
- CVSS changed · 6.9
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 15, 2026 – Oct 15, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
9 on the record
- github.com/ericmj/decimal/commit/6a523f3a73b8c9974540e21c7aa88f1258bb35ae
- github.com/ericmj/decimal/releases/tag/v2.4.0
- github.com/ericmj/decimal/commit/bc11f4a2b6fb61fc1360a0ab4e79141bba918841
- cna.erlef.org/cves/CVE-2026-32686.html
- github.com/advisories/GHSA-rhv4-8758-jx7v
- github.com/ericmj/decimal/security/advisories/GHSA-rhv4-8758-jx7v
- github.com/ericmj/decimal/releases/tag/v3.0.0
- osv.dev/vulnerability/EEF-CVE-2026-32686
- nvd.nist.gov/vuln/detail/CVE-2026-32686
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-97853 Unbounded allocation in decimal Decimal.round/3 driven by the places argument enables DoS 4d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-32686 is "Unbounded exponent in decimal enables unauthenticated DoS", rated Medium. It affects Decimal (Ericmj); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.9 describes technical severity. EPSS 0.34% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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