CVE-2026-39821VulnerabilityPublished 11 Aug 2026Updated 10 Nov 2026

SUSE · Security update for go-sendxmpp

Affects SUSESource GCVE Database

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Authoritative record:CVE-2026-39821· Critical 9.6

Not known to be exploited · CVSS 9.6 Critical · fixed in SUSE package updates : patch SUSE http as a priority.

Data as of 10 Nov 2026, 20:06 UTC

CVSS 3.1 base score

9.6Critical

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

Patch: Available – fixed in 1.27.0-rc.3, 1.26.6, 1.25.13 +1

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: High
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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 22 May 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 10 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

Upgrade net/http and net/http/internal/http2 to 1.27.0-rc.3, 1.26.6 or 1.25.13; golang.org/x/net/idna to 0.55.0.

Affected software

Product	Affected	Fixed in
Go standard librarynet/http	Affected >=1.27.0-0 <1.27.0-rc.3	Fixed in 1.27.0-rc.3
Go standard librarynet/http	Affected >=1.26.0-0 <1.26.6	Fixed in 1.26.6
Go standard librarynet/http	Affected <1.25.13	Fixed in 1.25.13
Go standard librarynet/http/internal/http2	Affected >=1.27.0-0 <1.27.0-rc.3	Fixed in 1.27.0-rc.3
Go standard librarynet/http/internal/http2	Affected >=1.26.0-0 <1.26.6	Fixed in 1.26.6
Go standard librarynet/http/internal/http2	Affected <1.25.13	Fixed in 1.25.13

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

Description

This update for go-sendxmpp fixes the following issues: Changes in go-sendxmpp: - Update to 0.17.0: * Add --ox-transfer-private-key to transfer the encrypted private key to PEP to transfer it to other devices (requires go-xmpp >= v0.3.7). * Add --ox-receive-private-key to receive the encrypted private key from PEP. * Add config option no_root_warning. * Add config option no_legacy_pgp_warning. * Also disable legacy PGP when running as root (Ox was already disabled). * Disable pinning for not using PLAIN when running as root. * Add config option ox_trust_mode with settings blind and tofu. * Due to new tofu trust mode for Ox, only one public key per contact is accepted for easier ID handling. * Ox: Check that fingerprint of received key equals the advertised one. * CVE-2026-39821: Failure to reject ASCII-only Punycode-encoded labels allows for validation bypass and privilege escalation (bsc#1266617): Bump net to 0.57.0

References

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