CVE-2026-552009.2CriticalCWE-680
CVE-2026-55200: libssh2 vulnerability
Vendor fix available · Affected: libssh2 · Exploitation: public proof of concept (unverified)
ExploitationProof of concept public
Not in CISA KEV as of catalogue 2026.11.13 (13 Nov)
- In CISA KEV: not seen
- Exploited (reported): not seen
- Scanning observed: not seen
- Proof of concept public3 public GitHub repositories (unverified), listed by PoC-in-GitHub23 Jun
- Not established: not seen
3.9%probability of exploitation in the next 30 days
90th percentile
050100
Higher than 90% of scored CVEs
9.2CriticalCVSS 4.0
LowMediumHighCrit.
DescriptionNVD
libssh2 1.11.1, fixed in commit 97acf3d, contains an out-of-bounds write vulnerability in ssh2_transport_read() that fails to enforce upper bounds on packet_length field. Remote attackers can send crafted SSH packets with excessively large packet_length values to corrupt heap memory and achieve remote code execution.
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
What changed
- PoC-in-GitHub lists 3 public GitHub repositories (unverified) PoC-in-GitHub
Coverage2 articles · 2 outlets
One row per outlet, in order of first report. First in our coverage: SecurityOnline, 23 Jun.
Quiet for 20 weekslast report 29 Jun2 articles2 outlets
- Tue 23 Jun, 02:30 UTC. SecurityOnline, first report. Libssh2 flaw CVE-2026-55200 allows remote code execution.
- Mon 29 Jun, 08:10 UTC. The Hacker News, its first report on the story. Public PoC released for critical libssh2 SSH flaw CVE-2026-55200.
- First report
- Article
- Running total
Show as tableHide table
| Published (UTC) | Outlet | Headline |
|---|---|---|
| 23 Jun 02:30 | SecurityOnline | Libssh2 flaw CVE-2026-55200 allows remote code execution |
| 29 Jun 08:10 | The Hacker News | Public PoC released for critical libssh2 SSH flaw CVE-2026-55200 |
- Libssh2 flaw CVE-2026-55200 allows remote code executionSecurityOnline · first in our coverage
New articles also arrive in the RSS feed.