VulnerabilityPublished 12 Nov 2026Updated 13 Nov 2026

CVE-2026-124077: Libcommons codec java · The GitIdentifiers class in Apache Commons Codec did not reject NUL bytes in

Affects libcommons-codec-javaSource GCVE Database

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Authoritative record:CVE-2026-124077· Medium 4.3

Not known to be exploited · CVSS 4.3 Medium · fixed in 1.23.0 : update libcommons-codec-java when convenient.

Data as of 13 Nov 2026, 22:04 UTC

CVSS 3.1 base score

4.3Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CISA-ADP	CVSS 3.1	4.3

Patch: Available – fixed in 1.23.0

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.10libcommons-codec-java`pkg:deb/ubuntu/libcommons-codec-java?arch=source&distro=stonking`Other threats	Affected =1.18.0-1 =1.22.0-1	Fixed in–
Ubuntu 26.04 LTSlibcommons-codec-java`pkg:deb/ubuntu/libcommons-codec-java?arch=source&distro=resolute`Other threats	Affected =1.18.0-1	Fixed in–
Ubuntu 24.04 LTSlibcommons-codec-java`pkg:deb/ubuntu/libcommons-codec-java?arch=source&distro=noble`Other threats	Affected =1.15-1 =1.16.0-1	Fixed in–
Ubuntu 22.04 LTSlibcommons-codec-java`pkg:deb/ubuntu/libcommons-codec-java?arch=source&distro=jammy`Other threats	Affected =1.15-1	Fixed in–
Ubuntu 20.04 LTSlibcommons-codec-java`pkg:deb/ubuntu/libcommons-codec-java?arch=source&distro=focal`Other threats	Affected =1.11-1 =1.14-1	Fixed in–
Ubuntu 18.04 LTSlibcommons-codec-java`pkg:deb/ubuntu/libcommons-codec-java?arch=source&distro=bionic`Other threats	Affected =1.10-1 =1.11-1	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

The GitIdentifiers class in Apache Commons Codec did not reject NUL bytes in tree entry names. Because Git uses a NUL byte to mark the end of each entry name in a tree object, a crafted name could make one tree serialize to the same bytes as a different tree. Two different directory trees could then receive the same Git tree identifier or SWHID. The impact is limited: common file systems do not allow NUL bytes in file names, so trees built by walking a file system are not affected. Only applications that build trees from names supplied by other sources, such as entries of archive formats that permit NUL bytes in names (e.g. ZIP) or names passed directly to the API, are exposed. This issue affects Apache Commons Codec: from 1.22.0 before 1.23.0. Users are recommended to upgrade to version 1.23.0, which fixes the issue.

References

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