Low Memory corruption

CVE-2026-18739 — Popt-devel: popt-static: off-by-one in poptstuffargs

A flaw was found in popt, a command-line option parsing library. An off-by-one error in the poptStuffArgs function, when repeatedly called by a host application or through deep alias nesting, can lead to corruption of internal program data. This corruption could potentially enable a local attacker to execute arbitrary code if the host application then unsafely processes the altered data.

Published Aug 4, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: redhat

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.1% (30-day exploitation probability)+0

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.14%

ahead of 3% of scored CVEs · Oct 15, 2026

Affects

Red Hat

Hardened Images and 7 more

CVSS base

2.5

Low · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Red Hat Hardened Images, Red Hat Red Hat Enterprise Linux 10, Red Hat Red Hat Enterprise Linux 6…).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Red Hat	Hardened Images	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat Enterprise Linux 10	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat Enterprise Linux 6	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat Enterprise Linux 7	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat Enterprise Linux 8	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat Enterprise Linux 9	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Red Hat	Red Hat OpenShift Container Platform 4	versions not specified by the source	Vulnerable	CVE Program (cve.org) e CISA ADP
Rpm-software-management	Popt	≥ 1.1.1	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

High

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

Low

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
2.5	CVSS 3.1	Low	1.0	1.4	secalert@redhat.com via NIST National Vulnerability Database
2.5	CVSS 3.1	Low	—	—	redhat via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L (score shown at the top: secalert@redhat.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-787 · Out-of-bounds Write

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.

endpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

2026
Affected products added · rpm-software-management/popt, red hat/red hat hardened images, red hat/red hat enterprise linux 10, red hat/red hat ente
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
CVSS changed · 2.5
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Awaiting Analysis
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Aug 4, 2026 · redhat

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

3 on the record

bugzilla.redhat.com/show_bug.cgi
issue-tracking, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/security/cve/CVE-2026-18739
vdb-entry, x_refsource_REDHAT, NIST National Vulnerability Database
access.redhat.com/errata/RHSA-2026:56984
vendor-advisory, x_refsource_REDHAT, NIST National Vulnerability Database

Elsewhere on this site

Red Hat
every CVE for this vendor

Memory corruption
same class

CWE-787
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-89096 Nfs-utils: nfs-utils: denial of service via memory leak in rpc.statd 23m
Medium CVE-2026-89088 Parted: parted: denial of service via heap buffer overflow during fat16 resize 23m
Medium CVE-2026-89085 Parted: parted: heap-based buffer overflow via crafted fat32 filesystem image 23m
Medium CVE-2026-111802 Nautilus: nautilus: arbitrary file deletion via trash symlink 23m
Low CVE-2026-17591 Libarchive: libarchive: use-after-free via aliased mac metadata copy 23m
Medium CVE-2026-62438 Gimp: gimp: paa integer overflow out-of-bounds read 1h

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-18739 is "Popt-devel: popt-static: off-by-one in poptstuffargs", rated Low. It affects Hardened Images (Red Hat); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 2.5 describes technical severity. EPSS 0.14% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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