CVE-2023-26557
io.finnet tss-lib before 2.0.0 can leak the lambda value of a private key via a timing side-channel attack because it relies on Go big.Int, which is not constant time for Cmp, modular exponentiation, or modular inverse.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.86%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
io.finnet tss-lib before 2.0.0 can leak the lambda value of a private key via a timing side-channel attack because it relies on Go big.Int, which is not constant time for Cmp, modular exponentiation, or modular inverse. An example leak is in crypto/paillier/paillier.go. (bnb-chain/tss-lib and thorchain/tss are also affected.)
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 0.86% probability · 57th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-203
- Affected
- iofinnet/tss-lib
- Source
- cve@mitre.org
EPSS 0.9% since 8 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/IoFinnet/tss-lib/releases/tag/v2.0.0Release Notes
- https://github.com/bnb-chain/tss-lib/tree/v1.3.5Product
- https://gitlab.com/thorchain/tss/tss-lib/-/tags/v0.1.3Release Notes
- https://medium.com/%40iofinnet/security-disclosure-for-ecdsa-and-eddsa-threshold-signature-schemes-4e969af7155b
- https://github.com/IoFinnet/tss-lib/releases/tag/v2.0.0Release Notes
- https://github.com/bnb-chain/tss-lib/tree/v1.3.5Product
- https://gitlab.com/thorchain/tss/tss-lib/-/tags/v0.1.3Release Notes
- https://medium.com/%40iofinnet/security-disclosure-for-ecdsa-and-eddsa-threshold-signature-schemes-4e969af7155b
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.