Denial of Service via Oversized Package Upload
Uncontrolled Resource Consumption vulnerability in hexpm hexpm/hexpm allows Excessive Allocation. Publishing an oversized package can cause Hex.pm to run out of memory while extracting the uploaded package tarball. This can terminate the affected application instance and result in a denial of service for package publishing and potentially other package-processing functionality. This issue affects hex.pm: before 2026-03-10.
- Published
- Mar 13, 2026
- Updated
- Sep 8, 2026
- EPSS
- 0.4% · 36th percentile
- CWE
- CWE-400
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
28
Monitor
Low priority for now.
- CVSS
- 28 / 40 · 7.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · EEF
- 7.1
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| hex | hexpm | cpe:2.3:a:hex:hexpm |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- hex hexpmbefore 2026-03-09
Versions reported by the vendor
Affected version ranges reported by the assigning authority (EEF). Independent of NVD's CPE analysis and usually ahead of it.
hexpm hexpm
- before 2026-03-10affected · date
- 82911daf5f8fb2ab44f298e3ba22b90bc1ae3746 and later · before 495f01607d3eae4aed7ad09b2f54f31ec7a7df01affected · git
Same product
hex: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-21622Password Reset Tokens Do Not Expire38Monitor
- CVE-2026-21618Cross-site scripting (XSS) in OAuth Device Authorization screen34Monitor
- CVE-2026-21621Improper Scope Enforcement in OAuth client_credentials Flow Allows Read-Only API Key to Escalate to Full Access28Monitor
- CVE-2026-23939Path Traversal in Local File Store Backend27Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| hexpm hexpm | 2026-03-10 | Vendor (CNA) |
| hexpm hexpm | 495f01607d3eae4aed7ad09b2f54f31ec7a7df01 | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Joud Zakharia / zentrust partners GmbHfinder
- Eric Meadows-Jönsson / Hex.pmremediation developer
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-400 · Uncontrolled Resource ConsumptionCVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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
nvd-secondary
Root cause
Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.
The bug in code
The whole CWE-400 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
function expand(node) { return node.children.map(expand);}Fixed
const MAX_DEPTH = 32;function expand(node, depth = 0) { if (depth > MAX_DEPTH) throw new Error("too deep"); return node.children.map((c) => expand(c, depth + 1));}Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- cna.erlef.org/cves/CVE-2026-23940.html
- github.com/hexpm/hexpm/commit/495f01607d3eae4aed7ad09b2f54f31ec7a7df01
- github.com/hexpm/hexpm/commit/82911daf5f8fb2ab44f298e3ba22b90bc1ae3746
- github.com/hexpm/hexpm/security/advisories/GHSA-jp8w-gxf6-8hcr
- osv.dev/vulnerability/EEF-CVE-2026-23940
Vendor advisories and official records. Exploit/PoC links are deliberately left out.