VulnSocial

CVE-2026-55008Patch(microsoft / exchange_server)

MEDIUMCVSS 9.6 · CRITICAL

Exploitation ongoing with high activity in latest observed window (1 mentions)

Immediate actions

  • Patch microsoft exchange_server systems immediately
  • Assume compromise if assets are exposed

Recommended action window: Immediate (within 24h)

NVD description

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.

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4.0/ 10 priority

Sources & remediation

Vendor / third-party advisories
Weakness type (CWE)
CWE-79

Priority

MEDIUM

Exploitation

ACTIVE

PoC

NONE

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

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

  • exchange_server
  • exchange_server_subscription_edition

Threat summary

  • Active exploitation appears in 1 classified signals
  • Patch or workaround signal is available
  • 2 mentions across 2 observed days
  • Momentum state: stable

What's happening

  • Active exploitation reported across 1 signal
  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 2 signals
  • Peaked 1d ago at 1 mentions (2026-07-15); latest day: 1
  • 2 total mentions across 2 days

Affected systems

Vendors
microsoft
Products
exchange_serverexchange_server_subscription_edition

2 versions affected across 2 products

Deep dive

Activity timeline2 mentions / 2d
00111Mentions · 2026-07-15: 1Mentions · 2026-07-16: 1Active Exploitation · 2026-07-16: 1Patch / Workaround · 2026-07-15: 1Technical Details · 2026-07-15: 1Technical Details · 2026-07-16: 107-1507-16
Signal classification2 categories
Patch
150.0%
Active Exploitation
150.0%
Referenced assets2 URLs
Classification over time
DateTotalLabels
2026-07-151
Patch1
2026-07-161
Active Exploitation1
Full discourse2 posts
  • Autumn Good@autumn_good_35
    Active Exploitation

    今月気になるのは、既に悪用されていて今後も悪用されそうなADFSの権限昇格（CVE-2026-56155）、認証不要でのRDPのRCE（CVE-2026-56190）、あとはOWAでメール開くだけでスクリプト実行できる（CVE-2026-55008）は悪用されそうですね。 The July 2026 Security Update Review https://www.zerodayinitiative.com/blog/2026/7/14/the-july-2026-security-update-review

    Post summary

    The tweet reports that CVE-2026-56155 has already been abused in the wild and warns that other listed vulnerabilities may also see active exploitation this month.

    200311.4K
    7.1K followersView on X
  • Windows Forum@windowsforum
    Patch

    🪟 Exchange admins, July’s critical XSS patch is a 9.6-rated “drop everything” moment—especially for internet-facing Outlook on the web. Patch now, before attackers turn OWA into their playground. https://windowsforum.com/threads/cve-2026-55008-install-july-exchange-updates-for-critical-xss.438877/?utm_source=x&utm_medium=social&utm_campaign=news_node84 #ExchangeSecurity #MicrosoftExchange #Cve202655008 https://t.co/OZmbRRJ4Do

    Post summary

    The tweet urges Exchange administrators to immediately apply the July 2026 CVE‑2026‑55008 XSS patch to prevent potential exploitation of Outlook Web Access.

    0100044
    1.2K followersView on X
CPE platform detail4 entries

4 of 4 entries

PartVendorProductVersionTarget SWTarget HW
Appmicrosoftexchange_server2016--
Appmicrosoftexchange_server2019--
Appmicrosoftexchange_server2019--
Appmicrosoftexchange_server_subscription_edition---

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