CVE-2026-53524

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (39th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 6.5Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

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 v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
45
EG Risk 45/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity65% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.5%
EPSS %ILE
39th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 21, 2026

Last Modified

September 9, 2026

Advisory Details (1)

Auto-updated Aug 21, 2026
Patch available. Sources: github.
githubMentions a patch (unverified)

Decompression Bomb in Relay WebSocket (DoS) · Advisory · weechat/weechat · GitHub

https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
weechat3.8-1 ... 4.9.5-1 (20 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
weechat4.10.0-1 ... 4.9.5-1 (8 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
weechat4.6.3-1, 4.7.2-1, 4.8.1-1, 4.9.0-1
  • every version up to 4.9.3-1: fixed in 4.9.3-1
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 48× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-09 20:07 UTCEPSS rescore
  2. 2026-10-09 05:38 UTCEG score recompute
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  25. 2026-09-26 15:59 UTCEPSS rescore
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  1. 2026-09-25 00:53 UTCEG score recompute
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  4. 2026-09-23 17:54 UTCEPSS rescore
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  8. 2026-09-20 20:16 UTCEPSS rescore
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  27. 2026-09-07 16:01 UTCEPSS rescore
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  38. 2026-08-31 01:18 UTCEG score recompute
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  40. 2026-08-30 01:22 UTCEPSS rescore
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  42. 2026-08-28 21:41 UTCEPSS rescore
  43. 2026-08-27 20:52 UTCEG score recompute
  44. 2026-08-27 14:25 UTCEPSS rescore
  45. 2026-08-26 20:46 UTCEG score recompute
  46. 2026-08-26 14:46 UTCEPSS rescore
  47. 2026-08-25 20:37 UTCEG score recompute
  48. 2026-08-25 13:49 UTCEPSS rescore
  49. 2026-08-24 20:27 UTCEG score recompute
  50. 2026-08-24 20:12 UTCEG score recompute
  51. 2026-08-23 23:39 UTCEG score recompute
  52. 2026-08-23 00:19 UTCEPSS rescore
  53. 2026-08-21 23:26 UTCEG score recompute
  54. 2026-08-21 22:29 UTCEG score recompute
  55. 2026-08-21 22:29 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-53524?
CVE-2026-53524 is a medium vulnerability published on August 21, 2026. 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 relaywebsocketinflate() has no upper bound on output size. An authenticated relay user can send a small compressed…
When was CVE-2026-53524 disclosed?
CVE-2026-53524 was first published on August 21, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-53524 actively exploited?
CVE-2026-53524 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (39th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-53524?
CVE-2026-53524 has a CVSS base score of 6.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-53524?
A fix for CVE-2026-53524 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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