CVE-2026-82736

Description

Incorrect Behavior Order: Validate Before Canonicalize vulnerability in ash-project ash lets an attacker store a case-insensitive string value that violates its length or match constraints. Ash.Type.CiString.apply_constraints/2 (lib/ash/type/ci_string.ex) validated the max_length, min_length, and match constraints against the value as submitted, while the type case-folds the string (per its casing) for storage and comparison. Because validation ran before folding, an attacker can submit a value whose folded form breaks a constraint but whose original form passes: for example, against a match pattern requiring uppercase, an uppercase value that is stored lowercased persists a value the pattern rejects. The fix case-folds the value at the start of apply_constraints/2, so the constraints are checked against the form that is actually stored. This issue affects ash: from 1.29.0-rc0 before 3.32.2.

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EPSS — Exploit Prediction

0.0014

Probability of exploitation

0.03%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-180 CWE-180

References

Other References

https://cna.erlef.org/cves/CVE-2026-82736.html https://github.com/ash-project/ash/commit/d8320b0127c8ef453679d70e5dd23a9506951d21 https://github.com/ash-project/ash/security/advisories/GHSA-gg9w-7593-hxg9 https://osv.dev/vulnerability/EEF-CVE-2026-82736 https://github.com/ash-project/ash/security/advisories/GHSA-gg9w-7593-hxg9

Frequently Asked Questions

What is CVE-2026-82736? +

Incorrect Behavior Order: Validate Before Canonicalize vulnerability in ash-project ash lets an attacker store a case-insensitive string value that violates its length or match constraints. Ash.Type.CiString.apply_constraints/2 (lib/ash/type/ci_string.ex) validated the max_length, min_length, and match constraints against the value as submitted, while the type case-folds the string (per its casing) for storage and comparison. Because validation ran before folding, an attacker can submit a value whose folded form breaks a constraint but whose original form passes: for example, against a match pattern requiring uppercase, an uppercase value that is stored lowercased persists a value the pattern rejects. The fix case-folds the value at the start of apply_constraints/2, so the constraints are checked against the form that is actually stored. This issue affects ash: from 1.29.0-rc0 before 3.32.2.

How do I check if I'm vulnerable to CVE-2026-82736? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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