6.5

CVE-2026-53524: weechat

CVSS: 6.5v3.1MediumDeferred
AliasesUBUNTU-CVE-2026-53524DEBIAN-CVE-2026-53524
Published 21-08-2026Last modified 24-08-2026
Open JSON

Vulnerability summary

CVE-2026-53524 is a medium (CVSS 6.5) vulnerability in weechat. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 40.6% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.48%
0%100%
Low · +0.22 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 2
OPENSUSE-SU-2026:11481-1OPENSUSE-SU-2026:21615-1

Timeline

  1. 21-08-2026
    PublishedVulnerability first disclosed.
  2. 24-08-2026
    Last modifiedVulnerability information updated.

Description

WeeChat (Wee Enhanced Environment for Chat) is a free chat client. In versions 4.3.0 through 4.9.0, the WeeChat relay module's WebSocket permessage-deflate decompression function relay_websocket_inflate() has no upper bound on output size. An authenticated relay user can send a small compressed WebSocket frame (~100 bytes) that decompresses to gigabytes, exhausting all server memory and crashing the entire WeeChat process. The api protocol enables permessage-deflate and requires authentication before WebSocket upgrade. Version 4.9.1 patches the issue.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.48%

Chance of exploitation in the next 30 days

Percentile

41%

Versus all other CVEs

30-day change

+0.22 pp

From 0.27% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.48%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • weechatAll versions (No fix recorded) | < 4.9.3-1
Ubuntu1 product
  • weechatAll versions (No fix recorded)
Weechat1 product

3 vendors · 3 products

References

5 links