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EEF-CVE-2026-48593 CVE-2026-48593 GHSA-6xh2-93p9-vqh4

Unbounded range expansion in cron describe causes memory exhaustion in oban_web

Medium Hex
Severity
0.0 / 10
Medium · CVSS 4.0
Exploit chance (EPSS)
0.42%
Chance of exploitation in the next 30 days. Higher than 36.01% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-400 Uncontrolled Resource Consumption
Fix
2.12.5
Upgrade oban_web to this version or later

Description

Summary

Uncontrolled Resource Consumption vulnerability in oban-bg oban_web ('Elixir.Oban.Web.CronExpr' modules) allows memory exhaustion via unbounded cron range expansion.

An attacker with access to schedule cron jobs can submit a malicious cron expression such as "0 0 1-100000000 * *". When a user with dashboard access views the cron job list, 'Elixir.Oban.Web.CronExpr':describe/1 is called to render the expression. parse_range/1 parses both range endpoints via Integer.parse/1 with no bounds check, and the downstream helpers expand_dom_parts/1 and expand_dow_parts/1 materialise the range eagerly via Enum.to_list/1, causing allocation of ~2.4 GB and stalling or crashing the BEAM node. A sibling helper extract_dom_values already validates range bounds, but the expansion helpers do not.

This issue affects oban_web: from 2.12.0 before 2.12.5.

Configurations

The vulnerability is exploitable when an attacker with access to schedule cron jobs submits a malicious cron expression. The crash is triggered when a user with dashboard access views the cron job list, which calls 'Elixir.Oban.Web.CronExpr':describe/1 to render the expression.

Affected versions

Hex

PackageVulnerableFixed in
oban_web
>= 2.12.0, < 2.12.5
2.12.5

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

oban_web Hex → 2.12.5

mix
{:oban_web, "~> 2.12.5"} # then: mix deps.update oban_web

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Attack vector
Network
Attack complexity
Low
Attack requirements
Present
Privileges required
Low
User interaction
Passive
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
None
Availability (vulnerable system)
High
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None

Weakness

CWE-400: Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

How to prevent it
  • Architecture and Design: Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
  • Architecture and Design: Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed. The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
  • Architecture and Design: Ensure that protocols have specific limits of scale placed on them.
  • Implementation: Ensure that all failures in resource allocation place the system into a safe posture.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
EEF-CVE-2026-48592
Missing authorization check on save-job event handler in oban_web
Medium Also affects oban_web
GHSA-cggf-277g-3q54
pypdf has possible large memory usage when parsing page tree
High Same weakness, CWE-400
GHSA-3g3m-2fjr-6pw4
Glob: AbortSignal cancellation bypass allows post-timeout filesystem traversal
Medium Same weakness, CWE-400
GHSA-42gh-23hr-vphw
pypdf has possible long runtimes when retrieving page labels
High Same weakness, CWE-400
GHSA-4vqv-7265-gm2w
pypdf has possible large memory usage for exceptions in strict mode
High Same weakness, CWE-400
GHSA-62m5-6wh8-28x7
pypdf has possible long runtimes/large memory usage for encrypted PDF files
High Same weakness, CWE-400
GHSA-7wch-p9px-956x
Forge: Regular expression denial of service in PEM decoding (pem.decode)
High Same weakness, CWE-400
GHSA-fw5c-8223-6h42
russh: peer-declared zero maximum packet size permanently stalls channel writes (silent AsyncWrite hang)
Medium Same weakness, CWE-400

Credits: Jonatan Männchen / EEF, Peter Ullrich, Shannon Selbert

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