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Fencer Vulns
medium 5.3

CVE-2026-32322 json

soroban-sdk: `Fr` scalar field equality comparison bypasses modular reduction

published 2026-03-12 7 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-11726 , GHSA-x2hw-px52-wp4m

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits
0
none known

Summary

soroban-sdk is a Rust SDK for Soroban contracts. Prior to 22.0.11, 23.5.3, and 25.3.0, The Fr (scalar field) types for BN254 and BLS12-381 in soroban-sdk compared values using their raw U256 representation without first reducing modulo the field modulus r. This caused mathematically equal field elements to compare as not-equal when one or both values were unreduced (i.e., >= r). The vulnerability requires an attacker to supply crafted Fr values through contract inputs, and compare them directly without going through host-side arithmetic operations. Smart contracts that rely on Fr equality checks for security-critical logic could produce incorrect results. The impact depends on how the affected contract uses Fr equality comparisons, but can result in incorrect authorization decisions or validation bypasses in contracts that perform equality checks on user-supplied scalar values. This vulnerability is fixed in 22.0.11, 23.5.3, and 25.3.0.

Patch / fix

  • crates.io soroban-sdk 22.0.11, 23.5.3, 25.3.0
  • stellar rs-soroban-sdk 22.0.11, 23.5.3, 25.3.0

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected packages

ecosystem package affected fixed in
crates.io soroban-sdk
>=25.0.0, <25.3.0
>=23.0.0, <23.5.3
<22.0.11
25.3.0
23.5.3
22.0.11

Affected products

  • stellar rs-soroban-sdk

Classification

Weakness

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.