CVE-2026-25506 [High] | Out-of-bounds Write in Munge

MUNGE is an authentication service for creating and validating user credentials. From 0.5 to 0.5.17, local attacker can exploit a buffer overflow vulnerability in munged (the MUNGE authentication daemon) to leak cryptographic key material from process memory. With the leaked key material, the attacker could forge arbitrary MUNGE credentials to impersonate any user (including root) to services that rely on MUNGE for authentication. The vulnerability allows a buffer overflow by sending a crafted message with an oversized address length field, corrupting munged's internal state and enabling extraction of the MAC subkey used for credential verification. This vulnerability is fixed in 0.5.18.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.02%	0.27%	+0.25%
2	2026-02-11	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.02%

0.27%

+0.25%

2026-02-11

—

0.02%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.7	3.1	HIGH	`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:L) Might cause slowdowns, glitches, or partial disruption—not a full brick.	1.1	6.0	[email protected]
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.7

3.1

HIGH

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:L Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:L): Might cause slowdowns, glitches, or partial disruption—not a full brick.

1.1

6.0

[email protected]

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

[email protected]

OS Trackers for CVE-2026-25506

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2026-25506 not yet assigned priority: Debian including 1 source packages (munge), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2026-25506
`redhat`	high	—	https://access.redhat.com/security/cve/CVE-2026-25506
`suse`	high	CVE-2026-25506 severity important: SUSE including 23 source package names (libmunge2-0.5.14-3.11.1, libmunge2-0.5.15-150400.18.10.1, …), 38 product×package rows across 12 product lines (SUSE Liberty Linux 8, SUSE Liberty Linux 9, … (12 product lines)): Fixed 38.	https://www.suse.com/security/cve/CVE-2026-25506/
`ubuntu`	medium	CVE-2026-25506 medium priority: Ubuntu including 1 source packages (munge), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): released 8.	https://ubuntu.com/security/CVE-2026-25506

Affected software / configurations for CVE-2026-25506

Vendor	Product	Version	Raw CPE
opensuse	munge	>= 0.5, < 0.5.18	cpe:2.3:a:opensuse:munge::::::::
debian	debian_linux	11.0	cpe:2.3:o:debian:debian_linux:11.0:::::::*

References for CVE-2026-25506

URL	Tags
https://github.com/dun/munge/commit/bf40cc27c4ce8451d4b062c9de0b67ec40894812	Patch
https://github.com/dun/munge/releases/tag/munge-0.5.18	Product Release Notes
https://github.com/dun/munge/security/advisories/GHSA-r9cr-jf4v-75gh	Mitigation Patch Vendor Advisory
http://www.openwall.com/lists/oss-security/2026/02/10/3	Mailing List Patch Third Party Advisory
http://www.openwall.com/lists/oss-security/2026/02/17/6	Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2026/02/msg00015.html	Mailing List Third Party Advisory

URL

CVE-2026-25506 | MUNGE has a buffer overflow in message unpacking allows key leakage and credential forgery

Exploit prediction scoring system (EPSS) score for CVE-2026-25506

Common vulnerability scoring system (CVSS) metrics for CVE-2026-25506

Weakness enumeration for CVE-2026-25506

OS Trackers for CVE-2026-25506

Affected software / configurations for CVE-2026-25506

References for CVE-2026-25506