Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
CISA KEV·Added 2026-06-05 — agencies required to remediate by 2026-06-19

CVE-2026-28318

HIGH

SolarWinds Serv-U is susceptible to specially crafted POST requests that crash the Serv-U service without authentication using Content-Encoding: deflate. Mitigation steps are provided…

Published
Jun 4, 2026
Updated
Jul 22, 2026
Affected
0 pkgs
Patched
None yet
Exploits
None indexed

EPSS Exploitation Probability

via FIRST.org ↗
8.4%probability of exploitation in next 30 days
Lower Risk94th percentile-2.31%
7.66%8.89%10.1%11.4%10.7%8.4%Jul 26Jul 26

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

SolarWinds Serv-U is susceptible to specially crafted POST requests that crash the Serv-U service without authentication using Content-Encoding: deflate. Mitigation steps are provided to secure customer environments in the SolarWinds Trust Center if you are unable to deploy the update

Affected Products

1 product · 2 configurations
Application
serv-usolarwinds
< 15.5.4
1 version
15.5.4

Detection & mitigation playbook

Vendor / appliance
  1. Detect

    Inventory every solarwinds serv-u deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

  2. Fix

    Apply the solarwinds serv-u security patch or hotfix for CVE-2026-28318 on the affected version, following the vendor advisory for your exact build.

  3. Workarounds

    Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

  4. How O3 protects you

    O3 detects and blocks CVE-2026-28318 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2026-28318. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

SolarWinds Serv-U is susceptible to specially crafted POST requests that crash the Serv-U service without authentication using Content-Encoding: deflate. Mitigation steps are provided to secure customer environments in the SolarWinds Trust Center if you are unable to deploy the update
O3 Security · Runtime Protection

Is CVE-2026-28318 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-28318 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.