CVE-2024-52791 | Denial of service through memory exhaustion in Matrix Media Repo

Matrix Media Repo (MMR) is a highly configurable multi-homeserver media repository for Matrix. MMR makes requests to other servers as part of normal operation, and these resource owners can return large amounts of JSON back to MMR for parsing. In parsing, MMR can consume large amounts of memory and exhaust available memory. This is fixed in MMR v1.3.8. Users are advised to upgrade. For users unable to upgrade; forward proxies can be configured to block requests to unsafe hosts. Alternatively, MMR processes can be configured with memory limits and auto-restart. Running multiple MMR processes concurrently can help ensure a restart does not overly impact users.

Published: 2025-01-16 Last update: 2025-08-20 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2024-52791 is rated Low Risk (28.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.07%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

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

Exploit prediction scoring system (EPSS) score for CVE-2024-52791

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 2026-02-24 0.41% 0.07% -0.33%
2 2025-11-21 0.52% 0.41% -0.11%
3 2025-11-18 0.52%

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-52791

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:L/PR:N/UI:N/S:U/C:N/I:N/A:L 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:N)
No account or special rights needed—anonymous or random user is enough.
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:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
3.9 1.4 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 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:N)
No account or special rights needed—anonymous or random user is enough.
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:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]

Weakness enumeration for CVE-2024-52791

GitHub Security Advisory for CVE-2024-52791

GHSA-gp86-q8hg-fpxj · Severity: medium · Ecosystem: go — matrix-media-repo (MMR) allows a denial of service through memory exhaustion

Affected software / configurations for CVE-2024-52791

Vendor Product Version Raw CPE
t2bot matrix-media-repo < 1.3.8 cpe:2.3:a:t2bot:matrix-media-repo:*:*:*:*:*:*:*:*

References for CVE-2024-52791

cvelogic Threat Intelligence