CVE-2026-55736: ash · Mass Assignment
Affects ashSource CVE Database V5
Not known to be exploited · CVSS 5.9 Medium : upgrade to 3.29.3 when convenient.
Data as of 5 Nov 2026, 00:01 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.29.3, d9b3100219b3ea86d73202bf7368c03a7688efea
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 23 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Upgrade ash to 3.29.3; ash to d9b3100219b3ea86d73202bf7368c03a7688efea.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| ash-projectash | Affected
| Fixed in
|
| ash-projectash | Affected
| Fixed in
|
Hexashpkg:hex/ashOther threats | Affected
| Fixed in
|
CPE configurations (1)
cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, applications using affected versions should avoid relying on private action arguments for critical authorization or ownership decisions or implement additional server-side validation to ensure private arguments cannot be overridden by user input.
Description
Improperly Controlled Modification of Dynamically-Determined Object Attributes vulnerability in ash-project ash allows a user to set the value of a private action argument that is intended to be controlled only by trusted server-side code. Action arguments declared with public?: false are meant to be set internally (for example via Ash.Changeset.set_private_argument/3) and must not be settable from end-user input. When a changeset is built from a parameter map, Ash filters out private arguments, but the filtering is incomplete. In the regular changeset path (for_create, for_update, for_destroy), private arguments are stripped only when the parameter key is an atom. When the key is a binary (string), as is the case for user-supplied parameters, the private argument is kept and the user controls its value. In the atomic path (Ash.Changeset.fully_atomic_changeset/4, also reached through atomic and bulk updates), private arguments are not stripped at all, regardless of whether the key is an atom or a binary. An attacker who can submit parameters to an action that defines a private argument can therefore inject a value for that argument. Depending on how the application uses the argument (for example an acting_user_id driving authorization or record ownership), this can lead to an integrity violation or privilege escalation. This issue affects ash: from 3.0.0 before 3.29.3.
References
- github.com/ash-project/ash/security/advisories/GHSA-f4hc-ppw9-4hhw (opens in a new tab)
- cna.erlef.org/cves/CVE-2026-55736.html (opens in a new tab)
- osv.dev/vulnerability/EEF-CVE-2026-55736 (opens in a new tab)
- github.com/ash-project/ash/commit/d9b3100219b3ea86d73202bf7368c03a7688efea (opens in a new tab)