Vulnerability · Published Sep 22, 2026 · Assigned by GitHub_M

CVE-2026-85725LightRAG: Plaintext Passwords Compared Without Constant-Time Function

Medium 5.9

In plain English

A medium-severity security flaw in LightRAG from HKUDS. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.9Medium

Exploit odds (30 days)0.4%top 61.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.5.5, verify_password in lightrag/api/passwords.py compares plaintext AUTH_ACCOUNTS password values with Python's == operator. The comparison can return after the first mismatching byte, creating response-time differences based on password length and matching prefixes. A network attacker with sufficiently low-latency access can repeatedly query the /login endpoint and use the timing oracle to recover a plaintext-configured password character by character. Deployments using bcrypt-prefixed password values are not affected by this comparison path. This issue is fixed in version 1.5.5.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	lightrag-hku	1.5.5	GHSA-c759-cx9p-mrwq
PyPI	lightrag-hku	1.5.5	PYSEC-2026-4061

Affected products (as reported)

Vendor	Product	Versions
HKUDS	LightRAG	< 1.5.5

Weakness: CWE-208 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

References

https://github.com/HKUDS/LightRAG/security/advisories/GHSA-c759-cx9p-mrwq x_refsource_CONFIRM
https://github.com/HKUDS/LightRAG/pull/3423 x_refsource_MISC
https://github.com/HKUDS/LightRAG/commit/89849c3ed0e0380345a6b5bade027cfb9a5bf32c x_refsource_MISC
https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5 x_refsource_MISC