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Fencer Vulns
low 2.1

CVE-2026-78691 json

Unescaped backslash allows LIKE wildcard injection in AshSql string search

published 2026-08-30 2 mo ago modified 2026-09-08 2 mo ago also EEF-CVE-2026-78691 , EUVD-2026-68188 , GHSA-5jgp-7mhc-6qqh

cvss
2.1
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

Improper Neutralization of Special Elements in Data Query Logic vulnerability in ash-project ash_sql allows a user who supplies a search term to contains/2, string_starts_with/2, or string_ends_with/2 to inject live SQL LIKE wildcards, turning a literal substring search into an attacker-controlled pattern match.

The escape helpers in AshSql.Expr prefix % and _ with a backslash but never escape a backslash already present in the input. Because backslash is the default LIKE escape character, the escaping defeats itself: the input \% becomes the pattern fragment \\%, where \\ is a literal backslash and the attacker's % remains a live wildcard. The search value stays parameterized, so this is confined to the LIKE pattern grammar rather than full SQL. An attacker can widen matches to probe values, slip past a negated contains(...) guard, or crash the query with a trailing lone backslash.

This issue affects ash_sql: from 0.1.1-rc.10 before 0.7.1.

Patch / fix

  • hex ash_sql 0.7.1
  • ash-project ash_sql 0.7.1

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/ash-project/ash_sql/security/advisories/GHSA-5jgp-7mhc-6qqh referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 2.1 CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
CNA 4.0 2.1 CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/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

Affected packages

ecosystem package affected fixed in
hex ash_sql
>=0.1.1-rc.10, <0.7.1
0.7.1

Affected products

  • ash-project ash_sql

Classification

Weakness
  • CWE-943 Improper Neutralization of Special Elements in Data Query Logic

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.