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Fencer Vulns
medium 5.5

CVE-2019-20334 json

In Netwide Assembler (NASM) 2.14.02, stack consumption occurs in expr# functions in asm/eval.c.

published 2020-01-04 6 y ago modified 2026-06-17 4 mo ago also EUVD-2019-10887

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 55%
public exploits
0
none known

Summary

In Netwide Assembler (NASM) 2.14.02, stack consumption occurs in expr# functions in asm/eval.c. This potentially affects the relationships among expr0, expr1, expr2, expr3, expr4, expr5, and expr6 (and stdscan in asm/stdscan.c). This is similar to CVE-2019-6290 and CVE-2019-6291.

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-2019-20334 updated cvss 6.2

nasm: stack consumption occurs in expr# functions in asm/eval.c

  • Red Hat Enterprise Linux 5 nasm Red Hat Enterprise Linux 6 nasm, nasm-rdoff
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 nasm, nasm-rdoff
    affected: no fix available “Fix deferred”

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

0.76% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugzilla.nasm.us https://bugzilla.nasm.us/show_bug.cgi?id=3392638 referenced PoC, tagged "exploit" by a source, unverified
  • bugzilla.nasm.us https://bugzilla.nasm.us/show_bug.cgi?id=3392548#c4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P

Classification

Weakness

References

Sources

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.