An exploitable use-after-free vulnerability exists in the HTTP server implementation of Cesanta Mongoose 6.8.

published 2017-11-07 9 y ago modified 2026-06-17 4 mo ago also EUVD-2017-12032

cvss: 9.8; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 2.8%; EPSS 2.8% chance of exploitation in 30 days, percentile 86%
public exploits: 0; none known

An exploitable use-after-free vulnerability exists in the HTTP server implementation of Cesanta Mongoose 6.8. An ordinary HTTP POST request with a CGI target can cause a reuse of previously freed pointer potentially resulting in remote code execution. An attacker needs to send this HTTP request over the network to trigger this vulnerability.

Patch / fix

distros 1

smplayer Debian 14, Debian 13, Debian 12 18.5.0~ds1-1

debian advisories DEBIAN-CVE-2017-2891

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2017-2891 updated 2026-01-13

mongoose: Multiple vulnerabilities fixed in version 6.8

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.76% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

talosintelligence.com https://www.talosintelligence.com/vulnerability_reports/TALOS-2017-0398 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.0	9.8	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

Cesanta Mongoose

Classification

Weakness

CWE-416 Use After Free

References

talosintelligence.com /vulnerability_reports/TALOS-2017-0398
exploit, technical-description, third-party-advisory

Sources

CVE List CVE-2017-2891
NVD CVE-2017-2891

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary