CVE-2026-54029 | LibreChat: IDOR in Message Deletion — Incomplete Fix for CVE-2024-41703 Leaves deleteMessages() Without User Filter

Exp

LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. Prior to 0.8.4-rc1, the DELETE /api/messages/:conversationId/:messageId endpoint allows any authenticated user to delete any other user's messages. The validateMessageReq middleware only validates that the conversationId belongs to the requesting user, but the handler calls deleteMessages({ messageId }) using only the messageId as the MongoDB filter — without adding a user constraint. An attacker provides their own valid conversationId (to pass validation) and the victim's messageId (to target deletion), resulting in permanent, irrecoverable message deletion. This vulnerability is fixed in 0.8.4-rc1.

Published: 2026-06-25 Last update: 2026-06-29 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-54029 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.15%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-54029

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-54029

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-26 0.03% 0.15% +0.12%
2 2026-06-12 0.03%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-54029

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
1.6 3.6 [email protected]
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 3.6 [email protected]

Weakness enumeration for CVE-2026-54029

Affected software / configurations for CVE-2026-54029

Vendor Product Version Raw CPE
librechat librechat <= 0.8.3 cpe:2.3:a:librechat:librechat:*:*:*:*:*:*:*:*

References for CVE-2026-54029

cvelogic Threat Intelligence