CVE-2025-8842: A vulnerability has been found in NASM Netwide Assember 2.17rc0

Routine

MEDIUM 5.3DOWNGRADE

CVE-2025-8842 is a medium-severity flaw (CVSS 5.3) affecting netwide assembler. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability has been found in NASM Netwide Assember 2.17rc0. Affected by this issue is the function do_directive of the file preproc.c. The manipulation leads to use after free. An attack has to be approached locally. The exploit has been disclosed to the public and may be used.

Why this priority

Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 85%)
CISA exploited list	No
Weakness	CWE-119, CWE-416
Published	2025-08-11
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: nasm

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-08-11 11:15 UTCPublished CVE record published
2026-06-17 10:07 UTCUpdated Record last modified

nasm netwide assembler DOWNGRADE

Affected: 2.17 rc0

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.17

1. Check installed version

apt-cache policy netwide-assembler || rpm -q netwide-assembler || netwide-assembler --version

2. No fixed release: DOWNGRADE to a release before 2.17 (Debian / Ubuntu)

apt-cache madison netwide-assembler sudo apt install netwide-assembler=<VERSION_BEFORE_2.17> sudo apt-mark hold netwide-assembler

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list netwide-assembler sudo dnf downgrade netwide-assembler-<VERSION_BEFORE_2.17> sudo dnf versionlock add netwide-assembler

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-8842?

netwide assembler: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-8842 being exploited?

CVE-2025-8842 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-8842 affect?

CVE-2025-8842 affects netwide assembler. Severity is medium (CVSS 5.3). A vulnerability has been found in NASM Netwide Assember 2.17rc0. Affected by this issue is the function do_directive of the file preproc.c. The manipulation leads to use after free. An attack has to be approached locally. The exploit has be

How urgent is CVE-2025-8842?

Priority 27/100. Public exploit reference

Related CVEs

CVE-2025-8846 MEDIUM 5.3 DOWNGRADE A vulnerability has been found in NASM Netwide Assember 2.17rc0
CVE-2025-8845 MEDIUM 5.3 DOWNGRADE A vulnerability was identified in NASM Netwide Assember 2.17rc0
CVE-2025-8844 LOW 3.3 DOWNGRADE A vulnerability was determined in NASM Netwide Assember 2.17rc0
CVE-2025-8843 MEDIUM 5.3 DOWNGRADE A vulnerability was found in NASM Netwide Assember 2.17rc0

References

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