Medium severity · published Sep 1, 2026
CVE-2026-82735
Match regex runs on over-length input in Ash.Type.String, enabling regex denial of service
5.9
CVSS
0.2%
EPSS
No
On KEV
Description
Uncontrolled Resource Consumption vulnerability in ash-project ash allows an attacker to force an expensive regular expression to run on input that a length constraint should have already rejected.
Ash.Type.String.apply_constraints/2 (lib/ash/type/string.ex) evaluated the :match regex regardless of the min_length and max_length constraints on the same attribute. Because the length check did not gate the regex, an over-length value that the length constraint rejects still had the pattern applied to it, so the length limit that would otherwise bound the work never constrained the regex input. Against a backtracking pattern this yields catastrophic regex evaluation on attacker-sized input, and even a linear pattern runs on arbitrarily large input, consuming CPU per request. The fix skips the :match regex whenever a length constraint is violated, making the two checks order-independent.
This issue affects ash: from 0.10.0 before 3.32.2.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 8% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AS
ash · ash-project
0.10.0 before 3.32.2; 05848d5f4affe60fddd812222a18ada080c0813b before 14928412a1a94a69c47df8e98920d3a2b09cdec4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-82735
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-82735
cna.erlef.org
https://cna.erlef.org/cves/CVE-2026-82735.html
github.com
https://github.com/ash-project/ash/commit/14928412a1a94a69c47df8e98920d3a2b09cdec4
github.com
https://github.com/ash-project/ash/security/advisories/GHSA-mq7g-pffw-m8xh
osv.dev
https://osv.dev/vulnerability/EEF-CVE-2026-82735
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