VulnSocial

CVE-2026-96259Disclosure(mattermost / mattermost_server)

LOWCVSS 5.5 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to apply the internal-connection filter to OAuth endpoint requests, which allows a System Administrator to make the server issue requests to internal network addresses and read the responses via the configured OAuth token and userinfo endpoints.. Mattermost Advisory ID: MMSA-2026-00776

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0.0/ 10 priority

Sources & remediation

Vendor / third-party advisories
Weakness type (CWE)
CWE-918

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • mattermost_server

Threat summary

  • 1 mentions across 1 observed day

What's happening

  • Technical details provided in 1 signal
  • Disclosure: 1 classified signal
  • 1 total mentions across 1 day

Affected systems

Vendors
mattermost
Products
mattermost_server

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-09-22: 1Technical Details · 2026-09-22: 109-22
Signal classification1 categories
Disclosure
1100.0%
Referenced assets1 URL
By indicator
Full discourse1 post
  • CVE@CVEnew
    Disclosure

    CVE-2026-96259 Mattermost versions 11.9.x &lt;= 11.9.1, 11.8.x &lt;= 11.8.5, 11.7.x &lt;= 11.7.10, 11.10.x &lt;= 11.10.1 fail to apply the internal-connection filter to OAuth endpoint requests,… https://www.cve.org/CVERecord?id=CVE-2026-96259

    Post summary

    The tweet discloses CVE-2026-96259, noting affected Mattermost versions and a missing internal-connection filter on OAuth endpoint requests, without mentioning patches, exploits, or active attacks.

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    58.1K followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Appmattermostmattermost_server---

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