Out-of-bounds Read in bfabiszewski/libmobi

published 2021-10-15 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-27113

cvss: 7.1; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.2%; EPSS 1.2% chance of exploitation in 30 days, percentile 67%
public exploits: 0; none known

libmobi is vulnerable to Out-of-bounds Read

Patch / fix

links 1

github.com/bfabiszewski/libmobi@bec783e commit

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-2021-3881 updated 2025-11-21 cvss 7.1

libmobi: out-of-bounds read in mobi_decompress_huffman_internal() in src/compression.c

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

1.16% chance of exploitation in the next 30 days, higher than 67% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

huntr.dev https://huntr.dev/bounties/540fd115-7de4-4e19-a918-5ee61f5157c1 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.0	7.1	CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
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

bfabiszewski bfabiszewski/libmobi

Classification

Weakness

CWE-125 Out-of-bounds Read

References

github.com /bfabiszewski/libmobi/commit/bec783e6212439a335ba6e8df7ab8ed610ca9a21
patch, third-party-advisory
huntr.dev /bounties/540fd115-7de4-4e19-a918-5ee61f5157c1
exploit, third-party-advisory

Sources

CVE List CVE-2021-3881
NVD CVE-2021-3881

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